diff --git a/Configuration/Geometry/python/dict2021Geometry.py b/Configuration/Geometry/python/dict2021Geometry.py
index b56111ffdea4d..c33590550d7ac 100644
--- a/Configuration/Geometry/python/dict2021Geometry.py
+++ b/Configuration/Geometry/python/dict2021Geometry.py
@@ -1394,7 +1394,7 @@
 muonDict = {
     "abbrev" : "M",
     "name" : "muon",
-    "default" : 1,
+    "default" : 4,
     "M1" : {
         1 : [
             'Geometry/MuonCommonData/data/mbCommon/2021/v2/mbCommon.xml',
@@ -1530,6 +1530,51 @@
         ],
         "era" : "run3_GEM",
     },
+    "M4" : {
+        1 : [
+            'Geometry/MuonCommonData/data/mbCommon/2021/v2/mbCommon.xml',
+            'Geometry/MuonCommonData/data/mb1/2021/v1/mb1.xml',
+            'Geometry/MuonCommonData/data/mb2/2021/v1/mb2.xml',
+            'Geometry/MuonCommonData/data/mb3/2021/v1/mb3.xml',
+            'Geometry/MuonCommonData/data/mb4/2015/v2/mb4.xml',
+            'Geometry/MuonCommonData/data/mb4Shield/2021/v1/mb4Shield.xml',
+            'Geometry/MuonCommonData/data/muonYoke/2021/v5/muonYoke.xml',
+            'Geometry/MuonCommonData/data/mf/2021/v3/mf.xml',
+            'Geometry/MuonCommonData/data/rpcf/2024/v1/rpcf.xml',
+            'Geometry/MuonCommonData/data/gemf/TDR_BaseLine/gemf.xml',
+            'Geometry/MuonCommonData/data/gem11/TDR_BaseLine/gem11.xml',
+            'Geometry/MuonCommonData/data/gem21/2024/v2/gem21.xml',
+            'Geometry/MuonCommonData/data/csc/2021/v3/csc.xml',
+            'Geometry/MuonCommonData/data/mfshield/2017/v2/mfshield.xml',
+        ],
+        2 : [
+            'Geometry/MuonCommonData/data/muonNumbering/2024/v1/muonNumbering.xml',
+        ],
+        3 : [
+            'Geometry/MuonSimData/data/muonSens/2021/v4/muonSens.xml',
+            'Geometry/DTGeometryBuilder/data/dtSpecsFilter/2021/v1/dtSpecsFilter.xml',
+            'Geometry/CSCGeometryBuilder/data/cscSpecsFilter.xml',
+            'Geometry/CSCGeometryBuilder/data/cscSpecs.xml',
+            'Geometry/RPCGeometryBuilder/data/2021/v1/RPCSpecs.xml',
+            'Geometry/GEMGeometryBuilder/data/GEMSpecsFilter/2021/v2/GEMSpecsFilter.xml',
+            'Geometry/GEMGeometryBuilder/data/GEMSpecs/2021/v2/GEMSpecs.xml',
+        ],
+        4 : [
+            'Geometry/MuonSimData/data/muonProdCuts/2021/v3/muonProdCuts.xml',
+        ],
+        "sim" : [
+            'from Geometry.MuonNumbering.muonGeometryConstants_cff import *',
+            'from Geometry.MuonNumbering.muonOffsetESProducer_cff import *',
+        ],
+        "reco" : [
+            'from Geometry.MuonNumbering.muonNumberingInitialization_cfi import *',
+            'from RecoMuon.DetLayers.muonDetLayerGeometry_cfi import *',
+            'from Geometry.GEMGeometryBuilder.gemGeometry_cff import *',
+            'from Geometry.CSCGeometryBuilder.idealForDigiCscGeometry_cff import *',
+            'from Geometry.DTGeometryBuilder.idealForDigiDtGeometry_cff import *',
+        ],
+        "era" : "run3_GEM",
+    },
 }
 
 forwardDict = {
@@ -1756,12 +1801,12 @@
     ("O5","T6","C1","M2","F2","P7") : "2023FlatMinus10Percent",
     ("O5","T7","C1","M2","F2","P7") : "2023FlatPlus05Percent",
     ("O5","T8","C1","M2","F2","P7") : "2023FlatPlus10Percent",
-    ("O6","T3","C1","M3","F3","P7") : "2024",
-    ("O4","T4","C1","M3","F2","P7") : "2024ZeroMaterial",
-    ("O5","T5","C1","M3","F2","P7") : "2024FlatMinus05Percent",
-    ("O5","T6","C1","M3","F2","P7") : "2024FlatMinus10Percent",
-    ("O5","T7","C1","M3","F2","P7") : "2024FlatPlus05Percent",
-    ("O5","T8","C1","M3","F2","P7") : "2024FlatPlus10Percent",
+    ("O6","T3","C1","M4","F3","P7") : "2024",
+    ("O4","T4","C1","M4","F2","P7") : "2024ZeroMaterial",
+    ("O5","T5","C1","M4","F2","P7") : "2024FlatMinus05Percent",
+    ("O5","T6","C1","M4","F2","P7") : "2024FlatMinus10Percent",
+    ("O5","T7","C1","M4","F2","P7") : "2024FlatPlus05Percent",
+    ("O5","T8","C1","M4","F2","P7") : "2024FlatPlus10Percent",
  }
 
 deprecatedSubdets = set([ "T1", "T2", "O1", "O2", "O3", "P1", "P2", "P3", 
diff --git a/Geometry/CMSCommonData/data/dd4hep/cmsExtendedGeometry2024.xml b/Geometry/CMSCommonData/data/dd4hep/cmsExtendedGeometry2024.xml
index cc7f72ccbd82c..c295ee780fb8e 100644
--- a/Geometry/CMSCommonData/data/dd4hep/cmsExtendedGeometry2024.xml
+++ b/Geometry/CMSCommonData/data/dd4hep/cmsExtendedGeometry2024.xml
@@ -246,7 +246,7 @@
     <Include ref='Geometry/MuonCommonData/data/rpcf/2024/v1/rpcf.xml'/>
     <Include ref='Geometry/MuonCommonData/data/gemf/TDR_BaseLine/gemf.xml'/>
     <Include ref='Geometry/MuonCommonData/data/gem11/TDR_BaseLine/gem11.xml'/>
-    <Include ref='Geometry/MuonCommonData/data/gem21/2024/v1/gem21.xml'/>
+    <Include ref='Geometry/MuonCommonData/data/gem21/2024/v2/gem21.xml'/>
     <Include ref='Geometry/MuonCommonData/data/csc/2021/v3/csc.xml'/>
     <Include ref='Geometry/MuonCommonData/data/mfshield/2017/v2/mfshield.xml'/>
     <Include ref='Geometry/MuonCommonData/data/muonNumbering/2024/v1/muonNumbering.xml'/>
diff --git a/Geometry/CMSCommonData/data/dd4hep/cmsExtendedGeometry2024FlatMinus05Percent.xml b/Geometry/CMSCommonData/data/dd4hep/cmsExtendedGeometry2024FlatMinus05Percent.xml
index b3e0cf8d73b4c..1b33189dd8342 100644
--- a/Geometry/CMSCommonData/data/dd4hep/cmsExtendedGeometry2024FlatMinus05Percent.xml
+++ b/Geometry/CMSCommonData/data/dd4hep/cmsExtendedGeometry2024FlatMinus05Percent.xml
@@ -246,7 +246,7 @@
     <Include ref='Geometry/MuonCommonData/data/rpcf/2024/v1/rpcf.xml'/>
     <Include ref='Geometry/MuonCommonData/data/gemf/TDR_BaseLine/gemf.xml'/>
     <Include ref='Geometry/MuonCommonData/data/gem11/TDR_BaseLine/gem11.xml'/>
-    <Include ref='Geometry/MuonCommonData/data/gem21/2024/v1/gem21.xml'/>
+    <Include ref='Geometry/MuonCommonData/data/gem21/2024/v2/gem21.xml'/>
     <Include ref='Geometry/MuonCommonData/data/csc/2021/v3/csc.xml'/>
     <Include ref='Geometry/MuonCommonData/data/mfshield/2017/v2/mfshield.xml'/>
     <Include ref='Geometry/MuonCommonData/data/muonNumbering/2024/v1/muonNumbering.xml'/>
diff --git a/Geometry/CMSCommonData/data/dd4hep/cmsExtendedGeometry2024FlatMinus10Percent.xml b/Geometry/CMSCommonData/data/dd4hep/cmsExtendedGeometry2024FlatMinus10Percent.xml
index 0b549faeffdb5..7ab66eca76578 100644
--- a/Geometry/CMSCommonData/data/dd4hep/cmsExtendedGeometry2024FlatMinus10Percent.xml
+++ b/Geometry/CMSCommonData/data/dd4hep/cmsExtendedGeometry2024FlatMinus10Percent.xml
@@ -246,7 +246,7 @@
     <Include ref='Geometry/MuonCommonData/data/rpcf/2024/v1/rpcf.xml'/>
     <Include ref='Geometry/MuonCommonData/data/gemf/TDR_BaseLine/gemf.xml'/>
     <Include ref='Geometry/MuonCommonData/data/gem11/TDR_BaseLine/gem11.xml'/>
-    <Include ref='Geometry/MuonCommonData/data/gem21/2024/v1/gem21.xml'/>
+    <Include ref='Geometry/MuonCommonData/data/gem21/2024/v2/gem21.xml'/>
     <Include ref='Geometry/MuonCommonData/data/csc/2021/v3/csc.xml'/>
     <Include ref='Geometry/MuonCommonData/data/mfshield/2017/v2/mfshield.xml'/>
     <Include ref='Geometry/MuonCommonData/data/muonNumbering/2024/v1/muonNumbering.xml'/>
diff --git a/Geometry/CMSCommonData/data/dd4hep/cmsExtendedGeometry2024FlatPlus05Percent.xml b/Geometry/CMSCommonData/data/dd4hep/cmsExtendedGeometry2024FlatPlus05Percent.xml
index 7e89e7f76962a..28ba4782ff227 100644
--- a/Geometry/CMSCommonData/data/dd4hep/cmsExtendedGeometry2024FlatPlus05Percent.xml
+++ b/Geometry/CMSCommonData/data/dd4hep/cmsExtendedGeometry2024FlatPlus05Percent.xml
@@ -246,7 +246,7 @@
     <Include ref='Geometry/MuonCommonData/data/rpcf/2024/v1/rpcf.xml'/>
     <Include ref='Geometry/MuonCommonData/data/gemf/TDR_BaseLine/gemf.xml'/>
     <Include ref='Geometry/MuonCommonData/data/gem11/TDR_BaseLine/gem11.xml'/>
-    <Include ref='Geometry/MuonCommonData/data/gem21/2024/v1/gem21.xml'/>
+    <Include ref='Geometry/MuonCommonData/data/gem21/2024/v2/gem21.xml'/>
     <Include ref='Geometry/MuonCommonData/data/csc/2021/v3/csc.xml'/>
     <Include ref='Geometry/MuonCommonData/data/mfshield/2017/v2/mfshield.xml'/>
     <Include ref='Geometry/MuonCommonData/data/muonNumbering/2024/v1/muonNumbering.xml'/>
diff --git a/Geometry/CMSCommonData/data/dd4hep/cmsExtendedGeometry2024FlatPlus10Percent.xml b/Geometry/CMSCommonData/data/dd4hep/cmsExtendedGeometry2024FlatPlus10Percent.xml
index ccafa1101aca3..6da00e25ac24e 100644
--- a/Geometry/CMSCommonData/data/dd4hep/cmsExtendedGeometry2024FlatPlus10Percent.xml
+++ b/Geometry/CMSCommonData/data/dd4hep/cmsExtendedGeometry2024FlatPlus10Percent.xml
@@ -246,7 +246,7 @@
     <Include ref='Geometry/MuonCommonData/data/rpcf/2024/v1/rpcf.xml'/>
     <Include ref='Geometry/MuonCommonData/data/gemf/TDR_BaseLine/gemf.xml'/>
     <Include ref='Geometry/MuonCommonData/data/gem11/TDR_BaseLine/gem11.xml'/>
-    <Include ref='Geometry/MuonCommonData/data/gem21/2024/v1/gem21.xml'/>
+    <Include ref='Geometry/MuonCommonData/data/gem21/2024/v2/gem21.xml'/>
     <Include ref='Geometry/MuonCommonData/data/csc/2021/v3/csc.xml'/>
     <Include ref='Geometry/MuonCommonData/data/mfshield/2017/v2/mfshield.xml'/>
     <Include ref='Geometry/MuonCommonData/data/muonNumbering/2024/v1/muonNumbering.xml'/>
diff --git a/Geometry/CMSCommonData/data/dd4hep/cmsExtendedGeometry2024ZeroMaterial.xml b/Geometry/CMSCommonData/data/dd4hep/cmsExtendedGeometry2024ZeroMaterial.xml
index 57341e9c01b50..f2deefc466045 100644
--- a/Geometry/CMSCommonData/data/dd4hep/cmsExtendedGeometry2024ZeroMaterial.xml
+++ b/Geometry/CMSCommonData/data/dd4hep/cmsExtendedGeometry2024ZeroMaterial.xml
@@ -246,7 +246,7 @@
     <Include ref='Geometry/MuonCommonData/data/rpcf/2024/v1/rpcf.xml'/>
     <Include ref='Geometry/MuonCommonData/data/gemf/TDR_BaseLine/gemf.xml'/>
     <Include ref='Geometry/MuonCommonData/data/gem11/TDR_BaseLine/gem11.xml'/>
-    <Include ref='Geometry/MuonCommonData/data/gem21/2024/v1/gem21.xml'/>
+    <Include ref='Geometry/MuonCommonData/data/gem21/2024/v2/gem21.xml'/>
     <Include ref='Geometry/MuonCommonData/data/csc/2021/v3/csc.xml'/>
     <Include ref='Geometry/MuonCommonData/data/mfshield/2017/v2/mfshield.xml'/>
     <Include ref='Geometry/MuonCommonData/data/muonNumbering/2024/v1/muonNumbering.xml'/>
diff --git a/Geometry/CMSCommonData/python/cmsExtendedGeometry2024FlatMinus05PercentXML_cfi.py b/Geometry/CMSCommonData/python/cmsExtendedGeometry2024FlatMinus05PercentXML_cfi.py
index 2084a4dd0c285..5dfe3fecfd6f4 100644
--- a/Geometry/CMSCommonData/python/cmsExtendedGeometry2024FlatMinus05PercentXML_cfi.py
+++ b/Geometry/CMSCommonData/python/cmsExtendedGeometry2024FlatMinus05PercentXML_cfi.py
@@ -247,7 +247,7 @@
         'Geometry/MuonCommonData/data/rpcf/2024/v1/rpcf.xml',
         'Geometry/MuonCommonData/data/gemf/TDR_BaseLine/gemf.xml',
         'Geometry/MuonCommonData/data/gem11/TDR_BaseLine/gem11.xml',
-        'Geometry/MuonCommonData/data/gem21/2024/v1/gem21.xml',
+        'Geometry/MuonCommonData/data/gem21/2024/v2/gem21.xml',
         'Geometry/MuonCommonData/data/csc/2021/v3/csc.xml',
         'Geometry/MuonCommonData/data/mfshield/2017/v2/mfshield.xml',
     )+
diff --git a/Geometry/CMSCommonData/python/cmsExtendedGeometry2024FlatMinus10PercentXML_cfi.py b/Geometry/CMSCommonData/python/cmsExtendedGeometry2024FlatMinus10PercentXML_cfi.py
index af4d28d14d58c..26ce0655d3520 100644
--- a/Geometry/CMSCommonData/python/cmsExtendedGeometry2024FlatMinus10PercentXML_cfi.py
+++ b/Geometry/CMSCommonData/python/cmsExtendedGeometry2024FlatMinus10PercentXML_cfi.py
@@ -247,7 +247,7 @@
         'Geometry/MuonCommonData/data/rpcf/2024/v1/rpcf.xml',
         'Geometry/MuonCommonData/data/gemf/TDR_BaseLine/gemf.xml',
         'Geometry/MuonCommonData/data/gem11/TDR_BaseLine/gem11.xml',
-        'Geometry/MuonCommonData/data/gem21/2024/v1/gem21.xml',
+        'Geometry/MuonCommonData/data/gem21/2024/v2/gem21.xml',
         'Geometry/MuonCommonData/data/csc/2021/v3/csc.xml',
         'Geometry/MuonCommonData/data/mfshield/2017/v2/mfshield.xml',
     )+
diff --git a/Geometry/CMSCommonData/python/cmsExtendedGeometry2024FlatPlus05PercentXML_cfi.py b/Geometry/CMSCommonData/python/cmsExtendedGeometry2024FlatPlus05PercentXML_cfi.py
index 28de997c5b4d6..b98ebeddf7f8b 100644
--- a/Geometry/CMSCommonData/python/cmsExtendedGeometry2024FlatPlus05PercentXML_cfi.py
+++ b/Geometry/CMSCommonData/python/cmsExtendedGeometry2024FlatPlus05PercentXML_cfi.py
@@ -247,7 +247,7 @@
         'Geometry/MuonCommonData/data/rpcf/2024/v1/rpcf.xml',
         'Geometry/MuonCommonData/data/gemf/TDR_BaseLine/gemf.xml',
         'Geometry/MuonCommonData/data/gem11/TDR_BaseLine/gem11.xml',
-        'Geometry/MuonCommonData/data/gem21/2024/v1/gem21.xml',
+        'Geometry/MuonCommonData/data/gem21/2024/v2/gem21.xml',
         'Geometry/MuonCommonData/data/csc/2021/v3/csc.xml',
         'Geometry/MuonCommonData/data/mfshield/2017/v2/mfshield.xml',
     )+
diff --git a/Geometry/CMSCommonData/python/cmsExtendedGeometry2024FlatPlus10PercentXML_cfi.py b/Geometry/CMSCommonData/python/cmsExtendedGeometry2024FlatPlus10PercentXML_cfi.py
index 8cb363c160f16..2a9bbb5bd4a4f 100644
--- a/Geometry/CMSCommonData/python/cmsExtendedGeometry2024FlatPlus10PercentXML_cfi.py
+++ b/Geometry/CMSCommonData/python/cmsExtendedGeometry2024FlatPlus10PercentXML_cfi.py
@@ -247,7 +247,7 @@
         'Geometry/MuonCommonData/data/rpcf/2024/v1/rpcf.xml',
         'Geometry/MuonCommonData/data/gemf/TDR_BaseLine/gemf.xml',
         'Geometry/MuonCommonData/data/gem11/TDR_BaseLine/gem11.xml',
-        'Geometry/MuonCommonData/data/gem21/2024/v1/gem21.xml',
+        'Geometry/MuonCommonData/data/gem21/2024/v2/gem21.xml',
         'Geometry/MuonCommonData/data/csc/2021/v3/csc.xml',
         'Geometry/MuonCommonData/data/mfshield/2017/v2/mfshield.xml',
     )+
diff --git a/Geometry/CMSCommonData/python/cmsExtendedGeometry2024XML_cfi.py b/Geometry/CMSCommonData/python/cmsExtendedGeometry2024XML_cfi.py
index b86ee3dcacb22..5f4809e555d64 100644
--- a/Geometry/CMSCommonData/python/cmsExtendedGeometry2024XML_cfi.py
+++ b/Geometry/CMSCommonData/python/cmsExtendedGeometry2024XML_cfi.py
@@ -247,7 +247,7 @@
         'Geometry/MuonCommonData/data/rpcf/2024/v1/rpcf.xml',
         'Geometry/MuonCommonData/data/gemf/TDR_BaseLine/gemf.xml',
         'Geometry/MuonCommonData/data/gem11/TDR_BaseLine/gem11.xml',
-        'Geometry/MuonCommonData/data/gem21/2024/v1/gem21.xml',
+        'Geometry/MuonCommonData/data/gem21/2024/v2/gem21.xml',
         'Geometry/MuonCommonData/data/csc/2021/v3/csc.xml',
         'Geometry/MuonCommonData/data/mfshield/2017/v2/mfshield.xml',
     )+
diff --git a/Geometry/CMSCommonData/python/cmsExtendedGeometry2024ZeroMaterialXML_cfi.py b/Geometry/CMSCommonData/python/cmsExtendedGeometry2024ZeroMaterialXML_cfi.py
index 8e6d1fea562ef..52e4bebac55da 100644
--- a/Geometry/CMSCommonData/python/cmsExtendedGeometry2024ZeroMaterialXML_cfi.py
+++ b/Geometry/CMSCommonData/python/cmsExtendedGeometry2024ZeroMaterialXML_cfi.py
@@ -247,7 +247,7 @@
         'Geometry/MuonCommonData/data/rpcf/2024/v1/rpcf.xml',
         'Geometry/MuonCommonData/data/gemf/TDR_BaseLine/gemf.xml',
         'Geometry/MuonCommonData/data/gem11/TDR_BaseLine/gem11.xml',
-        'Geometry/MuonCommonData/data/gem21/2024/v1/gem21.xml',
+        'Geometry/MuonCommonData/data/gem21/2024/v2/gem21.xml',
         'Geometry/MuonCommonData/data/csc/2021/v3/csc.xml',
         'Geometry/MuonCommonData/data/mfshield/2017/v2/mfshield.xml',
     )+