diff --git a/src/libraries/System.Collections.Immutable/ref/System.Collections.Immutable.cs b/src/libraries/System.Collections.Immutable/ref/System.Collections.Immutable.cs
index 8e452d7e1d1e3f..24f0119fcc29cd 100644
--- a/src/libraries/System.Collections.Immutable/ref/System.Collections.Immutable.cs
+++ b/src/libraries/System.Collections.Immutable/ref/System.Collections.Immutable.cs
@@ -219,10 +219,12 @@ public static System.Collections.Immutable.ImmutableArray<TResult> CreateRange<T
         public static System.Collections.Immutable.ImmutableArray<T> Create<T>(params T[]? items) { throw null; }
         public static System.Collections.Immutable.ImmutableArray<T> Create<T>(T[] items, int start, int length) { throw null; }
         public static System.Collections.Immutable.ImmutableArray<T> Create<T>(params System.ReadOnlySpan<T> items) { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static System.Collections.Immutable.ImmutableArray<T> Create<T>(System.Span<T> items) { throw null; }
         public static System.Collections.Immutable.ImmutableArray<TSource> ToImmutableArray<TSource>(this System.Collections.Generic.IEnumerable<TSource> items) { throw null; }
         public static System.Collections.Immutable.ImmutableArray<TSource> ToImmutableArray<TSource>(this System.Collections.Immutable.ImmutableArray<TSource>.Builder builder) { throw null; }
         public static System.Collections.Immutable.ImmutableArray<T> ToImmutableArray<T>(this System.ReadOnlySpan<T> items) { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static System.Collections.Immutable.ImmutableArray<T> ToImmutableArray<T>(this System.Span<T> items) { throw null; }
     }
     [System.Runtime.CompilerServices.CollectionBuilderAttribute(typeof(System.Collections.Immutable.ImmutableArray), "Create")]
diff --git a/src/libraries/System.Collections.Immutable/ref/System.Collections.Immutable.csproj b/src/libraries/System.Collections.Immutable/ref/System.Collections.Immutable.csproj
index 654ef839f48b06..098eeba7b3354c 100644
--- a/src/libraries/System.Collections.Immutable/ref/System.Collections.Immutable.csproj
+++ b/src/libraries/System.Collections.Immutable/ref/System.Collections.Immutable.csproj
@@ -19,6 +19,10 @@
     <Compile Include="System.Collections.Immutable.net9.cs" />
   </ItemGroup>
 
+  <ItemGroup Condition="!$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net9.0'))">
+    <Compile Include="$(CoreLibSharedDir)System\Runtime\CompilerServices\OverloadResolutionPriorityAttribute.cs" />
+  </ItemGroup>
+
   <ItemGroup Condition="'$(TargetFramework)' == '$(NetCoreAppCurrent)'">
     <ProjectReference Include="$(LibrariesProjectRoot)System.Collections\ref\System.Collections.csproj" />
     <ProjectReference Include="$(LibrariesProjectRoot)System.Runtime\ref\System.Runtime.csproj" />
@@ -28,4 +32,4 @@
     <PackageReference Include="System.Memory" Version="$(SystemMemoryVersion)" />
   </ItemGroup>
 
-</Project>
\ No newline at end of file
+</Project>
diff --git a/src/libraries/System.Collections.Immutable/src/System.Collections.Immutable.csproj b/src/libraries/System.Collections.Immutable/src/System.Collections.Immutable.csproj
index d2eac5d7d4577a..3f4bdabb2e37b6 100644
--- a/src/libraries/System.Collections.Immutable/src/System.Collections.Immutable.csproj
+++ b/src/libraries/System.Collections.Immutable/src/System.Collections.Immutable.csproj
@@ -156,6 +156,10 @@ The System.Collections.Immutable library is built-in as part of the shared frame
     <Compile Include="System\Collections\Frozen\String\OrdinalStringFrozenSet.AlternateLookup.cs" />
   </ItemGroup>
 
+  <ItemGroup Condition="!$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net9.0'))">
+    <Compile Include="$(CoreLibSharedDir)System\Runtime\CompilerServices\OverloadResolutionPriorityAttribute.cs" />
+  </ItemGroup>
+
   <ItemGroup Condition="'$(TargetFrameworkIdentifier)' != '.NETCoreApp'">
     <Compile Include="$(CoreLibSharedDir)System\Runtime\CompilerServices\CollectionBuilderAttribute.cs" Link="System\Runtime\CompilerServices\CollectionBuilderAttribute.cs" />
   </ItemGroup>
diff --git a/src/libraries/System.Collections.Immutable/src/System/Collections/Immutable/ImmutableArray.cs b/src/libraries/System.Collections.Immutable/src/System/Collections/Immutable/ImmutableArray.cs
index 15de249335b8f3..a170f53e66f240 100644
--- a/src/libraries/System.Collections.Immutable/src/System/Collections/Immutable/ImmutableArray.cs
+++ b/src/libraries/System.Collections.Immutable/src/System/Collections/Immutable/ImmutableArray.cs
@@ -4,6 +4,7 @@
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Linq;
+using System.Runtime.CompilerServices;
 
 namespace System.Collections.Immutable
 {
@@ -104,6 +105,7 @@ public static ImmutableArray<T> Create<T>(params ReadOnlySpan<T> items)
         /// <typeparam name="T">The type of element stored in the array.</typeparam>
         /// <param name="items">The elements to store in the array.</param>
         /// <returns>An immutable array containing the specified items.</returns>
+        [OverloadResolutionPriority(-1)]
         public static ImmutableArray<T> Create<T>(Span<T> items)
         {
             return Create((ReadOnlySpan<T>)items);
@@ -126,6 +128,7 @@ public static ImmutableArray<T> ToImmutableArray<T>(this ReadOnlySpan<T> items)
         /// <typeparam name="T">The type of element in the list.</typeparam>
         /// <param name="items">The elements to store in the array.</param>
         /// <returns>An immutable array containing the specified items.</returns>
+        [OverloadResolutionPriority(-1)]
         public static ImmutableArray<T> ToImmutableArray<T>(this Span<T> items)
         {
             return Create((ReadOnlySpan<T>)items);
diff --git a/src/libraries/System.Memory/ref/System.Memory.cs b/src/libraries/System.Memory/ref/System.Memory.cs
index f7b1f5f48d0f78..53d3da5e0441c2 100644
--- a/src/libraries/System.Memory/ref/System.Memory.cs
+++ b/src/libraries/System.Memory/ref/System.Memory.cs
@@ -222,73 +222,106 @@ public static partial class MemoryExtensions
         public static System.Span<T> AsSpan<T>(this T[]? array, int start, int length) { throw null; }
         public static System.Span<T> AsSpan<T>(this T[]? array, System.Range range) { throw null; }
         public static int BinarySearch<T>(this System.ReadOnlySpan<T> span, System.IComparable<T> comparable) { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static int BinarySearch<T>(this System.Span<T> span, System.IComparable<T> comparable) { throw null; }
         public static int BinarySearch<T, TComparer>(this System.ReadOnlySpan<T> span, T value, TComparer comparer) where TComparer : System.Collections.Generic.IComparer<T>, allows ref struct { throw null; }
         public static int BinarySearch<T, TComparable>(this System.ReadOnlySpan<T> span, TComparable comparable) where TComparable : System.IComparable<T>, allows ref struct { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static int BinarySearch<T, TComparer>(this System.Span<T> span, T value, TComparer comparer) where TComparer : System.Collections.Generic.IComparer<T>, allows ref struct { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static int BinarySearch<T, TComparable>(this System.Span<T> span, TComparable comparable) where TComparable : System.IComparable<T>, allows ref struct { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static int CommonPrefixLength<T>(this System.Span<T> span, System.ReadOnlySpan<T> other) { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static int CommonPrefixLength<T>(this System.Span<T> span, System.ReadOnlySpan<T> other, System.Collections.Generic.IEqualityComparer<T>? comparer) { throw null; }
         public static int CommonPrefixLength<T>(this System.ReadOnlySpan<T> span, System.ReadOnlySpan<T> other) { throw null; }
         public static int CommonPrefixLength<T>(this System.ReadOnlySpan<T> span, System.ReadOnlySpan<T> other, System.Collections.Generic.IEqualityComparer<T>? comparer) { throw null; }
         public static int CompareTo(this System.ReadOnlySpan<char> span, System.ReadOnlySpan<char> other, System.StringComparison comparisonType) { throw null; }
         public static bool Contains(this System.ReadOnlySpan<char> span, System.ReadOnlySpan<char> value, System.StringComparison comparisonType) { throw null; }
         public static bool Contains<T>(this System.ReadOnlySpan<T> span, T value) where T : System.IEquatable<T>? { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static bool Contains<T>(this System.Span<T> span, T value) where T : System.IEquatable<T>? { throw null; }
         public static bool ContainsAny(this System.ReadOnlySpan<char> span, System.Buffers.SearchValues<string> values) { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static bool ContainsAny(this System.Span<char> span, System.Buffers.SearchValues<string> values) { throw null; }
         public static bool ContainsAny<T>(this System.ReadOnlySpan<T> span, System.Buffers.SearchValues<T> values) where T : System.IEquatable<T>? { throw null; }
         public static bool ContainsAny<T>(this System.ReadOnlySpan<T> span, System.ReadOnlySpan<T> values) where T : System.IEquatable<T>? { throw null; }
         public static bool ContainsAny<T>(this System.ReadOnlySpan<T> span, T value0, T value1) where T : System.IEquatable<T>? { throw null; }
         public static bool ContainsAny<T>(this System.ReadOnlySpan<T> span, T value0, T value1, T value2) where T : System.IEquatable<T>? { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static bool ContainsAny<T>(this System.Span<T> span, System.Buffers.SearchValues<T> values) where T : System.IEquatable<T>? { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static bool ContainsAny<T>(this System.Span<T> span, System.ReadOnlySpan<T> values) where T : System.IEquatable<T>? { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static bool ContainsAny<T>(this System.Span<T> span, T value0, T value1) where T : System.IEquatable<T>? { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static bool ContainsAny<T>(this System.Span<T> span, T value0, T value1, T value2) where T : System.IEquatable<T>? { throw null; }
         public static bool ContainsAnyExcept<T>(this System.ReadOnlySpan<T> span, System.Buffers.SearchValues<T> values) where T : System.IEquatable<T>? { throw null; }
         public static bool ContainsAnyExcept<T>(this System.ReadOnlySpan<T> span, System.ReadOnlySpan<T> values) where T : System.IEquatable<T>? { throw null; }
         public static bool ContainsAnyExcept<T>(this System.ReadOnlySpan<T> span, T value) where T : System.IEquatable<T>? { throw null; }
         public static bool ContainsAnyExcept<T>(this System.ReadOnlySpan<T> span, T value0, T value1) where T : System.IEquatable<T>? { throw null; }
         public static bool ContainsAnyExcept<T>(this System.ReadOnlySpan<T> span, T value0, T value1, T value2) where T : System.IEquatable<T>? { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static bool ContainsAnyExcept<T>(this System.Span<T> span, System.Buffers.SearchValues<T> values) where T : System.IEquatable<T>? { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static bool ContainsAnyExcept<T>(this System.Span<T> span, System.ReadOnlySpan<T> values) where T : System.IEquatable<T>? { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static bool ContainsAnyExcept<T>(this System.Span<T> span, T value) where T : System.IEquatable<T>? { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static bool ContainsAnyExcept<T>(this System.Span<T> span, T value0, T value1) where T : System.IEquatable<T>? { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static bool ContainsAnyExcept<T>(this System.Span<T> span, T value0, T value1, T value2) where T : System.IEquatable<T>? { throw null; }
         public static bool ContainsAnyExceptInRange<T>(this System.ReadOnlySpan<T> span, T lowInclusive, T highInclusive) where T : System.IComparable<T> { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static bool ContainsAnyExceptInRange<T>(this System.Span<T> span, T lowInclusive, T highInclusive) where T : System.IComparable<T> { throw null; }
         public static bool ContainsAnyInRange<T>(this System.ReadOnlySpan<T> span, T lowInclusive, T highInclusive) where T : System.IComparable<T> { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static bool ContainsAnyInRange<T>(this System.Span<T> span, T lowInclusive, T highInclusive) where T : System.IComparable<T> { throw null; }
         public static void CopyTo<T>(this T[]? source, System.Memory<T> destination) { }
         public static void CopyTo<T>(this T[]? source, System.Span<T> destination) { }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static int Count<T>(this System.Span<T> span, T value) where T : System.IEquatable<T>? { throw null; }
         public static int Count<T>(this System.ReadOnlySpan<T> span, T value) where T : System.IEquatable<T>? { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static int Count<T>(this System.Span<T> span, System.ReadOnlySpan<T> value) where T : System.IEquatable<T>? { throw null; }
         public static int Count<T>(this System.ReadOnlySpan<T> span, System.ReadOnlySpan<T> value) where T : System.IEquatable<T>? { throw null; }
         public static bool EndsWith(this System.ReadOnlySpan<char> span, System.ReadOnlySpan<char> value, System.StringComparison comparisonType) { throw null; }
         public static bool EndsWith<T>(this System.ReadOnlySpan<T> span, System.ReadOnlySpan<T> value) where T : System.IEquatable<T>? { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static bool EndsWith<T>(this System.Span<T> span, System.ReadOnlySpan<T> value) where T : System.IEquatable<T>? { throw null; }
         public static bool EndsWith<T>(this System.ReadOnlySpan<T> span, T value) where T : System.IEquatable<T>? { throw null; }
         public static System.Text.SpanLineEnumerator EnumerateLines(this System.ReadOnlySpan<char> span) { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static System.Text.SpanLineEnumerator EnumerateLines(this System.Span<char> span) { throw null; }
         public static System.Text.SpanRuneEnumerator EnumerateRunes(this System.ReadOnlySpan<char> span) { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static System.Text.SpanRuneEnumerator EnumerateRunes(this System.Span<char> span) { throw null; }
         public static bool Equals(this System.ReadOnlySpan<char> span, System.ReadOnlySpan<char> other, System.StringComparison comparisonType) { throw null; }
         public static int IndexOf(this System.ReadOnlySpan<char> span, System.ReadOnlySpan<char> value, System.StringComparison comparisonType) { throw null; }
         public static int IndexOfAny(this System.ReadOnlySpan<char> span, System.Buffers.SearchValues<string> values) { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static int IndexOfAny(this System.Span<char> span, System.Buffers.SearchValues<string> values) { throw null; }
         public static int IndexOfAny<T>(this System.ReadOnlySpan<T> span, System.Buffers.SearchValues<T> values) where T : System.IEquatable<T>? { throw null; }
         public static int IndexOfAny<T>(this System.ReadOnlySpan<T> span, System.ReadOnlySpan<T> values) where T : System.IEquatable<T>? { throw null; }
         public static int IndexOfAny<T>(this System.ReadOnlySpan<T> span, T value0, T value1) where T : System.IEquatable<T>? { throw null; }
         public static int IndexOfAny<T>(this System.ReadOnlySpan<T> span, T value0, T value1, T value2) where T : System.IEquatable<T>? { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static int IndexOfAny<T>(this System.Span<T> span, System.Buffers.SearchValues<T> values) where T : System.IEquatable<T>? { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static int IndexOfAny<T>(this System.Span<T> span, System.ReadOnlySpan<T> values) where T : System.IEquatable<T>? { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static int IndexOfAny<T>(this System.Span<T> span, T value0, T value1) where T : System.IEquatable<T>? { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static int IndexOfAny<T>(this System.Span<T> span, T value0, T value1, T value2) where T : System.IEquatable<T>? { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static int IndexOfAnyExcept<T>(this System.Span<T> span, T value) where T : System.IEquatable<T>? { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static int IndexOfAnyExcept<T>(this System.Span<T> span, T value0, T value1) where T : System.IEquatable<T>? { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static int IndexOfAnyExcept<T>(this System.Span<T> span, T value0, T value1, T value2) where T : System.IEquatable<T>? { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static int IndexOfAnyExcept<T>(this System.Span<T> span, System.Buffers.SearchValues<T> values) where T : System.IEquatable<T>? { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static int IndexOfAnyExcept<T>(this System.Span<T> span, System.ReadOnlySpan<T> values) where T : System.IEquatable<T>? { throw null; }
         public static int IndexOfAnyExcept<T>(this System.ReadOnlySpan<T> span, T value) where T : System.IEquatable<T>? { throw null; }
         public static int IndexOfAnyExcept<T>(this System.ReadOnlySpan<T> span, T value0, T value1) where T : System.IEquatable<T>? { throw null; }
@@ -296,12 +329,16 @@ public static void CopyTo<T>(this T[]? source, System.Span<T> destination) { }
         public static int IndexOfAnyExcept<T>(this System.ReadOnlySpan<T> span, System.Buffers.SearchValues<T> values) where T : System.IEquatable<T>? { throw null; }
         public static int IndexOfAnyExcept<T>(this System.ReadOnlySpan<T> span, System.ReadOnlySpan<T> values) where T : System.IEquatable<T>? { throw null; }
         public static int IndexOfAnyExceptInRange<T>(this System.ReadOnlySpan<T> span, T lowInclusive, T highInclusive) where T : System.IComparable<T> { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static int IndexOfAnyExceptInRange<T>(this System.Span<T> span, T lowInclusive, T highInclusive) where T : System.IComparable<T> { throw null; }
         public static int IndexOf<T>(this System.ReadOnlySpan<T> span, System.ReadOnlySpan<T> value) where T : System.IEquatable<T>? { throw null; }
         public static int IndexOf<T>(this System.ReadOnlySpan<T> span, T value) where T : System.IEquatable<T>? { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static int IndexOf<T>(this System.Span<T> span, System.ReadOnlySpan<T> value) where T : System.IEquatable<T>? { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static int IndexOf<T>(this System.Span<T> span, T value) where T : System.IEquatable<T>? { throw null; }
         public static int IndexOfAnyInRange<T>(this System.ReadOnlySpan<T> span, T lowInclusive, T highInclusive) where T : System.IComparable<T> { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static int IndexOfAnyInRange<T>(this System.Span<T> span, T lowInclusive, T highInclusive) where T : System.IComparable<T> { throw null; }
         public static bool IsWhiteSpace(this System.ReadOnlySpan<char> span) { throw null; }
         public static int LastIndexOf(this System.ReadOnlySpan<char> span, System.ReadOnlySpan<char> value, System.StringComparison comparisonType) { throw null; }
@@ -309,14 +346,23 @@ public static void CopyTo<T>(this T[]? source, System.Span<T> destination) { }
         public static int LastIndexOfAny<T>(this System.ReadOnlySpan<T> span, System.ReadOnlySpan<T> values) where T : System.IEquatable<T>? { throw null; }
         public static int LastIndexOfAny<T>(this System.ReadOnlySpan<T> span, T value0, T value1) where T : System.IEquatable<T>? { throw null; }
         public static int LastIndexOfAny<T>(this System.ReadOnlySpan<T> span, T value0, T value1, T value2) where T : System.IEquatable<T>? { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static int LastIndexOfAny<T>(this System.Span<T> span, System.Buffers.SearchValues<T> values) where T : System.IEquatable<T>? { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static int LastIndexOfAny<T>(this System.Span<T> span, System.ReadOnlySpan<T> values) where T : System.IEquatable<T>? { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static int LastIndexOfAny<T>(this System.Span<T> span, T value0, T value1) where T : System.IEquatable<T>? { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static int LastIndexOfAny<T>(this System.Span<T> span, T value0, T value1, T value2) where T : System.IEquatable<T>? { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static int LastIndexOfAnyExcept<T>(this System.Span<T> span, T value) where T : System.IEquatable<T>? { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static int LastIndexOfAnyExcept<T>(this System.Span<T> span, T value0, T value1) where T : System.IEquatable<T>? { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static int LastIndexOfAnyExcept<T>(this System.Span<T> span, T value0, T value1, T value2) where T : System.IEquatable<T>? { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static int LastIndexOfAnyExcept<T>(this System.Span<T> span, System.Buffers.SearchValues<T> values) where T : System.IEquatable<T>? { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static int LastIndexOfAnyExcept<T>(this System.Span<T> span, System.ReadOnlySpan<T> values) where T : System.IEquatable<T>? { throw null; }
         public static int LastIndexOfAnyExcept<T>(this System.ReadOnlySpan<T> span, T value) where T : System.IEquatable<T>? { throw null; }
         public static int LastIndexOfAnyExcept<T>(this System.ReadOnlySpan<T> span, T value0, T value1) where T : System.IEquatable<T>? { throw null; }
@@ -324,25 +370,34 @@ public static void CopyTo<T>(this T[]? source, System.Span<T> destination) { }
         public static int LastIndexOfAnyExcept<T>(this System.ReadOnlySpan<T> span, System.Buffers.SearchValues<T> values) where T : System.IEquatable<T>? { throw null; }
         public static int LastIndexOfAnyExcept<T>(this System.ReadOnlySpan<T> span, System.ReadOnlySpan<T> values) where T : System.IEquatable<T>? { throw null; }
         public static int LastIndexOfAnyExceptInRange<T>(this System.ReadOnlySpan<T> span, T lowInclusive, T highInclusive) where T : System.IComparable<T> { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static int LastIndexOfAnyExceptInRange<T>(this System.Span<T> span, T lowInclusive, T highInclusive) where T : System.IComparable<T> { throw null; }
         public static int LastIndexOf<T>(this System.ReadOnlySpan<T> span, System.ReadOnlySpan<T> value) where T : System.IEquatable<T>? { throw null; }
         public static int LastIndexOf<T>(this System.ReadOnlySpan<T> span, T value) where T : System.IEquatable<T>? { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static int LastIndexOf<T>(this System.Span<T> span, System.ReadOnlySpan<T> value) where T : System.IEquatable<T>? { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static int LastIndexOf<T>(this System.Span<T> span, T value) where T : System.IEquatable<T>? { throw null; }
         public static int LastIndexOfAnyInRange<T>(this System.ReadOnlySpan<T> span, T lowInclusive, T highInclusive) where T : System.IComparable<T> { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static int LastIndexOfAnyInRange<T>(this System.Span<T> span, T lowInclusive, T highInclusive) where T : System.IComparable<T> { throw null; }
         public static bool Overlaps<T>(this System.ReadOnlySpan<T> span, System.ReadOnlySpan<T> other) { throw null; }
         public static bool Overlaps<T>(this System.ReadOnlySpan<T> span, System.ReadOnlySpan<T> other, out int elementOffset) { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static bool Overlaps<T>(this System.Span<T> span, System.ReadOnlySpan<T> other) { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static bool Overlaps<T>(this System.Span<T> span, System.ReadOnlySpan<T> other, out int elementOffset) { throw null; }
         public static void Replace<T>(this System.Span<T> span, T oldValue, T newValue) where T : System.IEquatable<T>? { }
         public static void Replace<T>(this System.ReadOnlySpan<T> source, System.Span<T> destination, T oldValue, T newValue) where T : System.IEquatable<T>? { }
         public static void Reverse<T>(this System.Span<T> span) { }
         public static int SequenceCompareTo<T>(this System.ReadOnlySpan<T> span, System.ReadOnlySpan<T> other) where T : System.IComparable<T>? { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static int SequenceCompareTo<T>(this System.Span<T> span, System.ReadOnlySpan<T> other) where T : System.IComparable<T>? { throw null; }
         public static bool SequenceEqual<T>(this System.ReadOnlySpan<T> span, System.ReadOnlySpan<T> other) where T : System.IEquatable<T>? { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static bool SequenceEqual<T>(this System.Span<T> span, System.ReadOnlySpan<T> other) where T : System.IEquatable<T>? { throw null; }
         public static bool SequenceEqual<T>(this System.ReadOnlySpan<T> span, System.ReadOnlySpan<T> other, System.Collections.Generic.IEqualityComparer<T>? comparer = null) { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static bool SequenceEqual<T>(this System.Span<T> span, System.ReadOnlySpan<T> other, System.Collections.Generic.IEqualityComparer<T>? comparer = null) { throw null; }
         public static void Sort<T>(this System.Span<T> span) { }
         public static void Sort<T>(this System.Span<T> span, System.Comparison<T> comparison) { }
@@ -360,6 +415,7 @@ public static void Sort<TKey, TValue, TComparer>(this System.Span<TKey> keys, Sy
         public static int SplitAny(this System.ReadOnlySpan<char> source, System.Span<System.Range> destination, System.ReadOnlySpan<string> separators, System.StringSplitOptions options = System.StringSplitOptions.None) { throw null; }
         public static bool StartsWith(this System.ReadOnlySpan<char> span, System.ReadOnlySpan<char> value, System.StringComparison comparisonType) { throw null; }
         public static bool StartsWith<T>(this System.ReadOnlySpan<T> span, System.ReadOnlySpan<T> value) where T : System.IEquatable<T>? { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public static bool StartsWith<T>(this System.Span<T> span, System.ReadOnlySpan<T> value) where T : System.IEquatable<T>? { throw null; }
         public static bool StartsWith<T>(this System.ReadOnlySpan<T> span, T value) where T : System.IEquatable<T>? { throw null; }
         public static int ToLower(this System.ReadOnlySpan<char> source, System.Span<char> destination, System.Globalization.CultureInfo? culture) { throw null; }
diff --git a/src/libraries/System.Numerics.Vectors/ref/System.Numerics.Vectors.cs b/src/libraries/System.Numerics.Vectors/ref/System.Numerics.Vectors.cs
index 443d0c64b6f1a0..fd00fe8c727068 100644
--- a/src/libraries/System.Numerics.Vectors/ref/System.Numerics.Vectors.cs
+++ b/src/libraries/System.Numerics.Vectors/ref/System.Numerics.Vectors.cs
@@ -762,6 +762,7 @@ public readonly void CopyTo(System.Span<float> destination) { }
         private readonly int _dummyPrimitive;
         public Vector(System.ReadOnlySpan<byte> values) { throw null; }
         public Vector(System.ReadOnlySpan<T> values) { throw null; }
+        [System.Runtime.CompilerServices.OverloadResolutionPriorityAttribute(-1)]
         public Vector(System.Span<T> values) { throw null; }
         public Vector(T value) { throw null; }
         public Vector(T[] values) { throw null; }
diff --git a/src/libraries/System.Private.CoreLib/src/System/MemoryExtensions.Globalization.cs b/src/libraries/System.Private.CoreLib/src/System/MemoryExtensions.Globalization.cs
index fac474c1b36913..5b64d503b836b8 100644
--- a/src/libraries/System.Private.CoreLib/src/System/MemoryExtensions.Globalization.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/MemoryExtensions.Globalization.cs
@@ -378,6 +378,7 @@ public static SpanRuneEnumerator EnumerateRunes(this ReadOnlySpan<char> span)
         /// <remarks>
         /// Invalid sequences will be represented in the enumeration by <see cref="Rune.ReplacementChar"/>.
         /// </remarks>
+        [OverloadResolutionPriority(-1)]
         public static SpanRuneEnumerator EnumerateRunes(this Span<char> span)
         {
             return new SpanRuneEnumerator(span);
@@ -404,6 +405,7 @@ public static SpanLineEnumerator EnumerateLines(this ReadOnlySpan<char> span)
         /// for <see cref="string.ReplaceLineEndings"/> for more information on how newline
         /// sequences are detected.
         /// </remarks>
+        [OverloadResolutionPriority(-1)]
         public static SpanLineEnumerator EnumerateLines(this Span<char> span)
         {
             return new SpanLineEnumerator(span);
diff --git a/src/libraries/System.Private.CoreLib/src/System/MemoryExtensions.cs b/src/libraries/System.Private.CoreLib/src/System/MemoryExtensions.cs
index ce8a3a83a7fc0d..174fac083981be 100644
--- a/src/libraries/System.Private.CoreLib/src/System/MemoryExtensions.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/MemoryExtensions.cs
@@ -313,6 +313,7 @@ public static ReadOnlyMemory<char> AsMemory(this string? text, Range range)
 
         /// <inheritdoc cref="Contains{T}(ReadOnlySpan{T}, T)"/>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [OverloadResolutionPriority(-1)]
         public static unsafe bool Contains<T>(this Span<T> span, T value) where T : IEquatable<T>? =>
             Contains((ReadOnlySpan<T>)span, value);
 
@@ -362,61 +363,73 @@ ref Unsafe.As<T, long>(ref MemoryMarshal.GetReference(span)),
 
         /// <inheritdoc cref="ContainsAny{T}(ReadOnlySpan{T}, T, T)"/>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [OverloadResolutionPriority(-1)]
         public static bool ContainsAny<T>(this Span<T> span, T value0, T value1) where T : IEquatable<T>? =>
             ContainsAny((ReadOnlySpan<T>)span, value0, value1);
 
         /// <inheritdoc cref="ContainsAny{T}(ReadOnlySpan{T}, T, T, T)"/>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [OverloadResolutionPriority(-1)]
         public static bool ContainsAny<T>(this Span<T> span, T value0, T value1, T value2) where T : IEquatable<T>? =>
             ContainsAny((ReadOnlySpan<T>)span, value0, value1, value2);
 
         /// <inheritdoc cref="ContainsAny{T}(ReadOnlySpan{T}, ReadOnlySpan{T})"/>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [OverloadResolutionPriority(-1)]
         public static bool ContainsAny<T>(this Span<T> span, ReadOnlySpan<T> values) where T : IEquatable<T>? =>
             ContainsAny((ReadOnlySpan<T>)span, values);
 
         /// <inheritdoc cref="ContainsAny{T}(ReadOnlySpan{T}, SearchValues{T})"/>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [OverloadResolutionPriority(-1)]
         public static bool ContainsAny<T>(this Span<T> span, SearchValues<T> values) where T : IEquatable<T>? =>
             ContainsAny((ReadOnlySpan<T>)span, values);
 
         /// <inheritdoc cref="ContainsAny(ReadOnlySpan{char}, SearchValues{string})"/>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [OverloadResolutionPriority(-1)]
         public static bool ContainsAny(this Span<char> span, SearchValues<string> values) =>
             ContainsAny((ReadOnlySpan<char>)span, values);
 
         /// <inheritdoc cref="ContainsAnyExcept{T}(ReadOnlySpan{T}, T)"/>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [OverloadResolutionPriority(-1)]
         public static bool ContainsAnyExcept<T>(this Span<T> span, T value) where T : IEquatable<T>? =>
             ContainsAnyExcept((ReadOnlySpan<T>)span, value);
 
         /// <inheritdoc cref="ContainsAnyExcept{T}(ReadOnlySpan{T}, T, T)"/>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [OverloadResolutionPriority(-1)]
         public static bool ContainsAnyExcept<T>(this Span<T> span, T value0, T value1) where T : IEquatable<T>? =>
             ContainsAnyExcept((ReadOnlySpan<T>)span, value0, value1);
 
         /// <inheritdoc cref="ContainsAnyExcept{T}(ReadOnlySpan{T}, T, T, T)"/>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [OverloadResolutionPriority(-1)]
         public static bool ContainsAnyExcept<T>(this Span<T> span, T value0, T value1, T value2) where T : IEquatable<T>? =>
             ContainsAnyExcept((ReadOnlySpan<T>)span, value0, value1, value2);
 
         /// <inheritdoc cref="ContainsAnyExcept{T}(ReadOnlySpan{T}, ReadOnlySpan{T})"/>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [OverloadResolutionPriority(-1)]
         public static bool ContainsAnyExcept<T>(this Span<T> span, ReadOnlySpan<T> values) where T : IEquatable<T>? =>
             ContainsAnyExcept((ReadOnlySpan<T>)span, values);
 
         /// <inheritdoc cref="ContainsAnyExcept{T}(ReadOnlySpan{T}, SearchValues{T})"/>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [OverloadResolutionPriority(-1)]
         public static bool ContainsAnyExcept<T>(this Span<T> span, SearchValues<T> values) where T : IEquatable<T>? =>
             ContainsAnyExcept((ReadOnlySpan<T>)span, values);
 
         /// <inheritdoc cref="ContainsAnyInRange{T}(ReadOnlySpan{T}, T, T)"/>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [OverloadResolutionPriority(-1)]
         public static bool ContainsAnyInRange<T>(this Span<T> span, T lowInclusive, T highInclusive) where T : IComparable<T> =>
             ContainsAnyInRange((ReadOnlySpan<T>)span, lowInclusive, highInclusive);
 
         /// <inheritdoc cref="ContainsAnyExceptInRange{T}(ReadOnlySpan{T}, T, T)"/>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [OverloadResolutionPriority(-1)]
         public static bool ContainsAnyExceptInRange<T>(this Span<T> span, T lowInclusive, T highInclusive) where T : IComparable<T> =>
             ContainsAnyExceptInRange((ReadOnlySpan<T>)span, lowInclusive, highInclusive);
 
@@ -580,6 +593,7 @@ public static bool ContainsAnyExceptInRange<T>(this ReadOnlySpan<T> span, T lowI
         /// <param name="span">The span to search.</param>
         /// <param name="value">The value to search for.</param>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [OverloadResolutionPriority(-1)]
         public static unsafe int IndexOf<T>(this Span<T> span, T value) where T : IEquatable<T>? =>
             IndexOf((ReadOnlySpan<T>)span, value);
 
@@ -589,6 +603,7 @@ public static unsafe int IndexOf<T>(this Span<T> span, T value) where T : IEquat
         /// <param name="span">The span to search.</param>
         /// <param name="value">The sequence to search for.</param>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [OverloadResolutionPriority(-1)]
         public static unsafe int IndexOf<T>(this Span<T> span, ReadOnlySpan<T> value) where T : IEquatable<T>? =>
             IndexOf((ReadOnlySpan<T>)span, value);
 
@@ -598,6 +613,7 @@ public static unsafe int IndexOf<T>(this Span<T> span, ReadOnlySpan<T> value) wh
         /// <param name="span">The span to search.</param>
         /// <param name="value">The value to search for.</param>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [OverloadResolutionPriority(-1)]
         public static unsafe int LastIndexOf<T>(this Span<T> span, T value) where T : IEquatable<T>? =>
             LastIndexOf((ReadOnlySpan<T>)span, value);
 
@@ -607,6 +623,7 @@ public static unsafe int LastIndexOf<T>(this Span<T> span, T value) where T : IE
         /// <param name="span">The span to search.</param>
         /// <param name="value">The sequence to search for.</param>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [OverloadResolutionPriority(-1)]
         public static unsafe int LastIndexOf<T>(this Span<T> span, ReadOnlySpan<T> value) where T : IEquatable<T>? =>
             LastIndexOf((ReadOnlySpan<T>)span, value);
 
@@ -618,6 +635,7 @@ public static unsafe int LastIndexOf<T>(this Span<T> span, ReadOnlySpan<T> value
         /// The index in the span of the first occurrence of any value other than <paramref name="value"/>.
         /// If all of the values are <paramref name="value"/>, returns -1.
         /// </returns>
+        [OverloadResolutionPriority(-1)]
         public static int IndexOfAnyExcept<T>(this Span<T> span, T value) where T : IEquatable<T>? =>
             IndexOfAnyExcept((ReadOnlySpan<T>)span, value);
 
@@ -630,6 +648,7 @@ public static int IndexOfAnyExcept<T>(this Span<T> span, T value) where T : IEqu
         /// The index in the span of the first occurrence of any value other than <paramref name="value0"/> and <paramref name="value1"/>.
         /// If all of the values are <paramref name="value0"/> or <paramref name="value1"/>, returns -1.
         /// </returns>
+        [OverloadResolutionPriority(-1)]
         public static int IndexOfAnyExcept<T>(this Span<T> span, T value0, T value1) where T : IEquatable<T>? =>
             IndexOfAnyExcept((ReadOnlySpan<T>)span, value0, value1);
 
@@ -643,6 +662,7 @@ public static int IndexOfAnyExcept<T>(this Span<T> span, T value0, T value1) whe
         /// The index in the span of the first occurrence of any value other than <paramref name="value0"/>, <paramref name="value1"/>, and <paramref name="value2"/>.
         /// If all of the values are <paramref name="value0"/>, <paramref name="value1"/>, or <paramref name="value2"/>, returns -1.
         /// </returns>
+        [OverloadResolutionPriority(-1)]
         public static int IndexOfAnyExcept<T>(this Span<T> span, T value0, T value1, T value2) where T : IEquatable<T>? =>
             IndexOfAnyExcept((ReadOnlySpan<T>)span, value0, value1, value2);
 
@@ -654,6 +674,7 @@ public static int IndexOfAnyExcept<T>(this Span<T> span, T value0, T value1, T v
         /// The index in the span of the first occurrence of any value other than those in <paramref name="values"/>.
         /// If all of the values are in <paramref name="values"/>, returns -1.
         /// </returns>
+        [OverloadResolutionPriority(-1)]
         public static int IndexOfAnyExcept<T>(this Span<T> span, ReadOnlySpan<T> values) where T : IEquatable<T>? =>
             IndexOfAnyExcept((ReadOnlySpan<T>)span, values);
 
@@ -666,6 +687,7 @@ public static int IndexOfAnyExcept<T>(this Span<T> span, ReadOnlySpan<T> values)
         /// If all of the values are in <paramref name="values"/>, returns -1.
         /// </returns>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [OverloadResolutionPriority(-1)]
         public static int IndexOfAnyExcept<T>(this Span<T> span, SearchValues<T> values) where T : IEquatable<T>? =>
             IndexOfAnyExcept((ReadOnlySpan<T>)span, values);
 
@@ -927,6 +949,7 @@ public static int IndexOfAnyExcept<T>(this ReadOnlySpan<T> span, SearchValues<T>
         /// The index in the span of the last occurrence of any value other than <paramref name="value"/>.
         /// If all of the values are <paramref name="value"/>, returns -1.
         /// </returns>
+        [OverloadResolutionPriority(-1)]
         public static int LastIndexOfAnyExcept<T>(this Span<T> span, T value) where T : IEquatable<T>? =>
             LastIndexOfAnyExcept((ReadOnlySpan<T>)span, value);
 
@@ -939,6 +962,7 @@ public static int LastIndexOfAnyExcept<T>(this Span<T> span, T value) where T :
         /// The index in the span of the last occurrence of any value other than <paramref name="value0"/> and <paramref name="value1"/>.
         /// If all of the values are <paramref name="value0"/> or <paramref name="value1"/>, returns -1.
         /// </returns>
+        [OverloadResolutionPriority(-1)]
         public static int LastIndexOfAnyExcept<T>(this Span<T> span, T value0, T value1) where T : IEquatable<T>? =>
             LastIndexOfAnyExcept((ReadOnlySpan<T>)span, value0, value1);
 
@@ -952,6 +976,7 @@ public static int LastIndexOfAnyExcept<T>(this Span<T> span, T value0, T value1)
         /// The index in the span of the last occurrence of any value other than <paramref name="value0"/>, <paramref name="value1"/>, and <paramref name="value2"/>.
         /// If all of the values are <paramref name="value0"/>, <paramref name="value1"/>, and <paramref name="value2"/>, returns -1.
         /// </returns>
+        [OverloadResolutionPriority(-1)]
         public static int LastIndexOfAnyExcept<T>(this Span<T> span, T value0, T value1, T value2) where T : IEquatable<T>? =>
             LastIndexOfAnyExcept((ReadOnlySpan<T>)span, value0, value1, value2);
 
@@ -963,6 +988,7 @@ public static int LastIndexOfAnyExcept<T>(this Span<T> span, T value0, T value1,
         /// The index in the span of the last occurrence of any value other than those in <paramref name="values"/>.
         /// If all of the values are in <paramref name="values"/>, returns -1.
         /// </returns>
+        [OverloadResolutionPriority(-1)]
         public static int LastIndexOfAnyExcept<T>(this Span<T> span, ReadOnlySpan<T> values) where T : IEquatable<T>? =>
             LastIndexOfAnyExcept((ReadOnlySpan<T>)span, values);
 
@@ -975,6 +1001,7 @@ public static int LastIndexOfAnyExcept<T>(this Span<T> span, ReadOnlySpan<T> val
         /// If all of the values are in <paramref name="values"/>, returns -1.
         /// </returns>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [OverloadResolutionPriority(-1)]
         public static int LastIndexOfAnyExcept<T>(this Span<T> span, SearchValues<T> values) where T : IEquatable<T>? =>
             LastIndexOfAnyExcept((ReadOnlySpan<T>)span, values);
 
@@ -1231,6 +1258,7 @@ public static int LastIndexOfAnyExcept<T>(this ReadOnlySpan<T> span, SearchValue
 
         /// <inheritdoc cref="IndexOfAnyInRange{T}(ReadOnlySpan{T}, T, T)"/>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [OverloadResolutionPriority(-1)]
         public static int IndexOfAnyInRange<T>(this Span<T> span, T lowInclusive, T highInclusive) where T : IComparable<T> =>
             IndexOfAnyInRange((ReadOnlySpan<T>)span, lowInclusive, highInclusive);
 
@@ -1295,6 +1323,7 @@ ref Unsafe.As<T, ulong>(ref MemoryMarshal.GetReference(span)),
 
         /// <inheritdoc cref="IndexOfAnyExceptInRange{T}(ReadOnlySpan{T}, T, T)"/>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [OverloadResolutionPriority(-1)]
         public static int IndexOfAnyExceptInRange<T>(this Span<T> span, T lowInclusive, T highInclusive) where T : IComparable<T> =>
             IndexOfAnyExceptInRange((ReadOnlySpan<T>)span, lowInclusive, highInclusive);
 
@@ -1359,6 +1388,7 @@ ref Unsafe.As<T, ulong>(ref MemoryMarshal.GetReference(span)),
 
         /// <inheritdoc cref="LastIndexOfAnyInRange{T}(ReadOnlySpan{T}, T, T)"/>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [OverloadResolutionPriority(-1)]
         public static int LastIndexOfAnyInRange<T>(this Span<T> span, T lowInclusive, T highInclusive) where T : IComparable<T> =>
             LastIndexOfAnyInRange((ReadOnlySpan<T>)span, lowInclusive, highInclusive);
 
@@ -1423,6 +1453,7 @@ ref Unsafe.As<T, ulong>(ref MemoryMarshal.GetReference(span)),
 
         /// <inheritdoc cref="LastIndexOfAnyExceptInRange{T}(ReadOnlySpan{T}, T, T)"/>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [OverloadResolutionPriority(-1)]
         public static int LastIndexOfAnyExceptInRange<T>(this Span<T> span, T lowInclusive, T highInclusive) where T : IComparable<T> =>
             LastIndexOfAnyExceptInRange((ReadOnlySpan<T>)span, lowInclusive, highInclusive);
 
@@ -1498,12 +1529,14 @@ private static void ThrowNullLowHighInclusive<T>(T? lowInclusive, T? highInclusi
         /// </summary>
         [Intrinsic] // Unrolled and vectorized for half-constant input
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [OverloadResolutionPriority(-1)]
         public static unsafe bool SequenceEqual<T>(this Span<T> span, ReadOnlySpan<T> other) where T : IEquatable<T>? =>
             SequenceEqual((ReadOnlySpan<T>)span, other);
 
         /// <summary>
         /// Determines the relative order of the sequences being compared by comparing the elements using IComparable{T}.CompareTo(T).
         /// </summary>
+        [OverloadResolutionPriority(-1)]
         public static int SequenceCompareTo<T>(this Span<T> span, ReadOnlySpan<T> other) where T : IComparable<T>? =>
             SequenceCompareTo((ReadOnlySpan<T>)span, other);
 
@@ -1654,6 +1687,7 @@ ref Unsafe.As<T, char>(ref MemoryMarshal.GetReference(value)),
         /// <param name="value0">One of the values to search for.</param>
         /// <param name="value1">One of the values to search for.</param>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [OverloadResolutionPriority(-1)]
         public static unsafe int IndexOfAny<T>(this Span<T> span, T value0, T value1) where T : IEquatable<T>? =>
             IndexOfAny((ReadOnlySpan<T>)span, value0, value1);
 
@@ -1665,6 +1699,7 @@ public static unsafe int IndexOfAny<T>(this Span<T> span, T value0, T value1) wh
         /// <param name="value1">One of the values to search for.</param>
         /// <param name="value2">One of the values to search for.</param>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [OverloadResolutionPriority(-1)]
         public static unsafe int IndexOfAny<T>(this Span<T> span, T value0, T value1, T value2) where T : IEquatable<T>? =>
             IndexOfAny((ReadOnlySpan<T>)span, value0, value1, value2);
 
@@ -1674,6 +1709,7 @@ public static unsafe int IndexOfAny<T>(this Span<T> span, T value0, T value1, T
         /// <param name="span">The span to search.</param>
         /// <param name="values">The set of values to search for.</param>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [OverloadResolutionPriority(-1)]
         public static int IndexOfAny<T>(this Span<T> span, ReadOnlySpan<T> values) where T : IEquatable<T>? =>
             IndexOfAny((ReadOnlySpan<T>)span, values);
 
@@ -1683,6 +1719,7 @@ public static int IndexOfAny<T>(this Span<T> span, ReadOnlySpan<T> values) where
         /// <param name="span">The span to search.</param>
         /// <param name="values">The set of values to search for.</param>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [OverloadResolutionPriority(-1)]
         public static int IndexOfAny<T>(this Span<T> span, SearchValues<T> values) where T : IEquatable<T>? =>
             IndexOfAny((ReadOnlySpan<T>)span, values);
 
@@ -1692,6 +1729,7 @@ public static int IndexOfAny<T>(this Span<T> span, SearchValues<T> values) where
         /// <param name="span">The span to search.</param>
         /// <param name="values">The set of values to search for.</param>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [OverloadResolutionPriority(-1)]
         public static int IndexOfAny(this Span<char> span, SearchValues<string> values) =>
             IndexOfAny((ReadOnlySpan<char>)span, values);
 
@@ -1903,6 +1941,7 @@ public static int IndexOfAny(this ReadOnlySpan<char> span, SearchValues<string>
         /// <param name="value0">One of the values to search for.</param>
         /// <param name="value1">One of the values to search for.</param>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [OverloadResolutionPriority(-1)]
         public static unsafe int LastIndexOfAny<T>(this Span<T> span, T value0, T value1) where T : IEquatable<T>? =>
             LastIndexOfAny((ReadOnlySpan<T>)span, value0, value1);
 
@@ -1914,6 +1953,7 @@ public static unsafe int LastIndexOfAny<T>(this Span<T> span, T value0, T value1
         /// <param name="value1">One of the values to search for.</param>
         /// <param name="value2">One of the values to search for.</param>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [OverloadResolutionPriority(-1)]
         public static unsafe int LastIndexOfAny<T>(this Span<T> span, T value0, T value1, T value2) where T : IEquatable<T>? =>
             LastIndexOfAny((ReadOnlySpan<T>)span, value0, value1, value2);
 
@@ -1923,6 +1963,7 @@ public static unsafe int LastIndexOfAny<T>(this Span<T> span, T value0, T value1
         /// <param name="span">The span to search.</param>
         /// <param name="values">The set of values to search for.</param>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [OverloadResolutionPriority(-1)]
         public static int LastIndexOfAny<T>(this Span<T> span, ReadOnlySpan<T> values) where T : IEquatable<T>? =>
             LastIndexOfAny((ReadOnlySpan<T>)span, values);
 
@@ -1932,6 +1973,7 @@ public static int LastIndexOfAny<T>(this Span<T> span, ReadOnlySpan<T> values) w
         /// <param name="span">The span to search.</param>
         /// <param name="values">The set of values to search for.</param>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [OverloadResolutionPriority(-1)]
         public static int LastIndexOfAny<T>(this Span<T> span, SearchValues<T> values) where T : IEquatable<T>? =>
             LastIndexOfAny((ReadOnlySpan<T>)span, values);
 
@@ -2147,6 +2189,7 @@ ref Unsafe.As<T, byte>(ref MemoryMarshal.GetReference(other)),
         /// <param name="other">The second sequence to compare.</param>
         /// <param name="comparer">The <see cref="IEqualityComparer{T}"/> implementation to use when comparing elements, or null to use the default <see cref="IEqualityComparer{T}"/> for the type of an element.</param>
         /// <returns>true if the two sequences are equal; otherwise, false.</returns>
+        [OverloadResolutionPriority(-1)]
         public static bool SequenceEqual<T>(this Span<T> span, ReadOnlySpan<T> other, IEqualityComparer<T>? comparer = null) =>
             SequenceEqual((ReadOnlySpan<T>)span, other, comparer);
 
@@ -2235,6 +2278,7 @@ ref Unsafe.As<T, char>(ref MemoryMarshal.GetReference(other)),
         /// </summary>
         [Intrinsic] // Unrolled and vectorized for half-constant input
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [OverloadResolutionPriority(-1)]
         public static unsafe bool StartsWith<T>(this Span<T> span, ReadOnlySpan<T> value) where T : IEquatable<T>? =>
             StartsWith((ReadOnlySpan<T>)span, value);
 
@@ -2263,6 +2307,7 @@ ref Unsafe.As<T, byte>(ref MemoryMarshal.GetReference(value)),
         /// </summary>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         [Intrinsic] // Unrolled and vectorized for half-constant input
+        [OverloadResolutionPriority(-1)]
         public static unsafe bool EndsWith<T>(this Span<T> span, ReadOnlySpan<T> value) where T : IEquatable<T>? =>
             EndsWith((ReadOnlySpan<T>)span, value);
 
@@ -2708,6 +2753,7 @@ public static void CopyTo<T>(this T[]? source, Memory<T> destination)
         /// Determines whether two sequences overlap in memory.
         /// </summary>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [OverloadResolutionPriority(-1)]
         public static bool Overlaps<T>(this Span<T> span, ReadOnlySpan<T> other) =>
             Overlaps((ReadOnlySpan<T>)span, other);
 
@@ -2715,6 +2761,7 @@ public static bool Overlaps<T>(this Span<T> span, ReadOnlySpan<T> other) =>
         /// Determines whether two sequences overlap in memory and outputs the element offset.
         /// </summary>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [OverloadResolutionPriority(-1)]
         public static bool Overlaps<T>(this Span<T> span, ReadOnlySpan<T> other, out int elementOffset) =>
             Overlaps((ReadOnlySpan<T>)span, other, out elementOffset);
 
@@ -2784,6 +2831,7 @@ ref MemoryMarshal.GetReference(span),
         /// <paramref name = "comparable" /> is <see langword="null"/> .
         /// </exception>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [OverloadResolutionPriority(-1)]
         public static int BinarySearch<T>(this Span<T> span, IComparable<T> comparable) =>
             BinarySearch((ReadOnlySpan<T>)span, comparable);
 
@@ -2805,6 +2853,7 @@ public static int BinarySearch<T>(this Span<T> span, IComparable<T> comparable)
         /// <paramref name = "comparable" /> is <see langword="null"/> .
         /// </exception>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [OverloadResolutionPriority(-1)]
         public static int BinarySearch<T, TComparable>(
             this Span<T> span, TComparable comparable)
             where TComparable : IComparable<T>, allows ref struct =>
@@ -2829,6 +2878,7 @@ public static int BinarySearch<T, TComparable>(
         /// <paramref name = "comparer" /> is <see langword="null"/> .
         /// </exception>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [OverloadResolutionPriority(-1)]
         public static int BinarySearch<T, TComparer>(
             this Span<T> span, T value, TComparer comparer)
             where TComparer : IComparer<T>, allows ref struct =>
@@ -3194,6 +3244,7 @@ ref Unsafe.As<T, long>(ref dst),
         /// <param name="span">The first sequence to compare.</param>
         /// <param name="other">The second sequence to compare.</param>
         /// <returns>The length of the common prefix shared by the two spans.  If there's no shared prefix, 0 is returned.</returns>
+        [OverloadResolutionPriority(-1)]
         public static int CommonPrefixLength<T>(this Span<T> span, ReadOnlySpan<T> other) =>
             CommonPrefixLength((ReadOnlySpan<T>)span, other);
 
@@ -3203,6 +3254,7 @@ public static int CommonPrefixLength<T>(this Span<T> span, ReadOnlySpan<T> other
         /// <param name="other">The second sequence to compare.</param>
         /// <param name="comparer">The <see cref="IEqualityComparer{T}"/> implementation to use when comparing elements, or null to use the default <see cref="IEqualityComparer{T}"/> for the type of an element.</param>
         /// <returns>The length of the common prefix shared by the two spans.  If there's no shared prefix, 0 is returned.</returns>
+        [OverloadResolutionPriority(-1)]
         public static int CommonPrefixLength<T>(this Span<T> span, ReadOnlySpan<T> other, IEqualityComparer<T>? comparer) =>
             CommonPrefixLength((ReadOnlySpan<T>)span, other, comparer);
 
@@ -3695,6 +3747,7 @@ private static (int StartInclusive, int EndExclusive) TrimSplitEntry(ReadOnlySpa
         /// <param name="span">The span to search.</param>
         /// <param name="value">The value for which to search.</param>
         /// <returns>The number of times <paramref name="value"/> was found in the <paramref name="span"/>.</returns>
+        [OverloadResolutionPriority(-1)]
         public static int Count<T>(this Span<T> span, T value) where T : IEquatable<T>? =>
             Count((ReadOnlySpan<T>)span, value);
 
@@ -3749,6 +3802,7 @@ ref MemoryMarshal.GetReference(span),
         /// <param name="span">The span to search.</param>
         /// <param name="value">The value for which to search.</param>
         /// <returns>The number of times <paramref name="value"/> was found in the <paramref name="span"/>.</returns>
+        [OverloadResolutionPriority(-1)]
         public static int Count<T>(this Span<T> span, ReadOnlySpan<T> value) where T : IEquatable<T>? =>
             Count((ReadOnlySpan<T>)span, value);
 
diff --git a/src/libraries/System.Private.CoreLib/src/System/Numerics/Vector_1.cs b/src/libraries/System.Private.CoreLib/src/System/Numerics/Vector_1.cs
index b2274943e51821..30a3cb9fa37287 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Numerics/Vector_1.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Numerics/Vector_1.cs
@@ -119,6 +119,7 @@ public Vector(ReadOnlySpan<byte> values)
         /// <param name="values">The span from which the vector is created.</param>
         /// <returns>A new <see cref="Vector{T}" /> with its elements set to the first <see cref="Vector{T}.Count" /> elements from <paramref name="values" />.</returns>
         /// <exception cref="ArgumentOutOfRangeException">The length of <paramref name="values" /> is less than <see cref="Vector{T}.Count" />.</exception>
+        [OverloadResolutionPriority(-1)]
         public Vector(Span<T> values) : this((ReadOnlySpan<T>)values)
         {
         }
diff --git a/src/libraries/System.Private.CoreLib/src/System/Runtime/CompilerServices/OverloadResolutionPriorityAttribute.cs b/src/libraries/System.Private.CoreLib/src/System/Runtime/CompilerServices/OverloadResolutionPriorityAttribute.cs
index f38d3195815b1d..33a8383d734727 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Runtime/CompilerServices/OverloadResolutionPriorityAttribute.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Runtime/CompilerServices/OverloadResolutionPriorityAttribute.cs
@@ -7,7 +7,12 @@ namespace System.Runtime.CompilerServices
     /// Specifies the priority of a member in overload resolution. When unspecified, the default priority is 0.
     /// </summary>
     [AttributeUsage(AttributeTargets.Method | AttributeTargets.Constructor | AttributeTargets.Property, AllowMultiple = false, Inherited = false)]
-    public sealed class OverloadResolutionPriorityAttribute : Attribute
+#if SYSTEM_PRIVATE_CORELIB
+    public
+#else
+    internal
+#endif
+    sealed class OverloadResolutionPriorityAttribute : Attribute
     {
         /// <summary>
         /// Initializes a new instance of the <see cref="OverloadResolutionPriorityAttribute"/> class.
diff --git a/src/libraries/System.Private.CoreLib/src/System/SpanHelpers.BinarySearch.cs b/src/libraries/System.Private.CoreLib/src/System/SpanHelpers.BinarySearch.cs
index 9815a4b5e66cb0..72fc2ddaec7645 100644
--- a/src/libraries/System.Private.CoreLib/src/System/SpanHelpers.BinarySearch.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/SpanHelpers.BinarySearch.cs
@@ -11,7 +11,7 @@ internal static partial class SpanHelpers
     {
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public static int BinarySearch<T, TComparable>(
-            this ReadOnlySpan<T> span, TComparable comparable)
+            ReadOnlySpan<T> span, TComparable comparable)
             where TComparable : IComparable<T>, allows ref struct
         {
             if (comparable == null)