diff --git a/packages/calcite-components/src/components/segmented-control/segmented-control.e2e.ts b/packages/calcite-components/src/components/segmented-control/segmented-control.e2e.ts
index d158d8a703f..014e30572f7 100644
--- a/packages/calcite-components/src/components/segmented-control/segmented-control.e2e.ts
+++ b/packages/calcite-components/src/components/segmented-control/segmented-control.e2e.ts
@@ -1,4 +1,4 @@
-import { E2EPage, newE2EPage } from "@stencil/core/testing";
+import { E2EElement, E2EPage, newE2EPage } from "@stencil/core/testing";
 import { html } from "../../../support/formatting";
 import {
   defaults,
@@ -380,17 +380,39 @@ describe("calcite-segmented-control", () => {
   });
 
   it("inheritable props: `appearance`, `layout`, and `scale` modified on the parent get passed to items", async () => {
+    async function inheritsProps(segmentedControlItems: E2EElement[]): Promise<void> {
+      for (const item of segmentedControlItems) {
+        expect(await item.getProperty("appearance")).toBe("outline");
+        expect(await item.getProperty("layout")).toBe("vertical");
+        expect(await item.getProperty("scale")).toBe("l");
+      }
+    }
+
     const page = await newE2EPage();
     await page.setContent(html`
-      <calcite-segmented-control appearance="outline" layout="vertical" scale="l"></calcite-segmented-control>
+      <calcite-segmented-control appearance="outline" layout="vertical" scale="l">
+        <calcite-segmented-control-item id="child-1" value="1">one</calcite-segmented-control-item>
+        <calcite-segmented-control-item id="child-2" value="2">two</calcite-segmented-control-item>
+        <calcite-segmented-control-item id="child-3" value="3">three</calcite-segmented-control-item>
+      </calcite-segmented-control>
     `);
-    const segmentedControlItems = await page.findAll("calcite-segmented-control-item");
+    await page.waitForChanges();
 
-    for (const item of segmentedControlItems) {
-      expect(await item.getProperty("appearance")).toBe("outline");
-      expect(await item.getProperty("layout")).toBe("vertical");
-      expect(await item.getProperty("scale")).toBe("l");
-    }
+    const segmentedControl = await page.find("calcite-segmented-control");
+
+    let segmentedControlItems = await page.findAll("calcite-segmented-control-item");
+    expect(segmentedControlItems).toHaveLength(3);
+    await inheritsProps(segmentedControlItems);
+
+    segmentedControl.innerHTML = html`
+      <calcite-segmented-control-item id="child-4" value="4">one</calcite-segmented-control-item>
+      <calcite-segmented-control-item id="child-5" value="5">two</calcite-segmented-control-item>
+    `;
+    await page.waitForChanges();
+
+    segmentedControlItems = await page.findAll("calcite-segmented-control-item");
+    expect(segmentedControlItems).toHaveLength(2);
+    await inheritsProps(segmentedControlItems);
   });
 
   describe("setFocus()", () => {
diff --git a/packages/calcite-components/src/components/segmented-control/segmented-control.tsx b/packages/calcite-components/src/components/segmented-control/segmented-control.tsx
index fb52158ddac..fb96cb4a527 100644
--- a/packages/calcite-components/src/components/segmented-control/segmented-control.tsx
+++ b/packages/calcite-components/src/components/segmented-control/segmented-control.tsx
@@ -11,7 +11,7 @@ import {
   VNode,
   Watch,
 } from "@stencil/core";
-import { getElementDir, toAriaBoolean } from "../../utils/dom";
+import { getElementDir, slotChangeGetAssignedElements, toAriaBoolean } from "../../utils/dom";
 import {
   afterConnectDefaultValueSet,
   connectForm,
@@ -33,7 +33,6 @@ import {
   setUpLoadableComponent,
 } from "../../utils/loadable";
 import { Appearance, Layout, Scale, Status, Width } from "../interfaces";
-import { createObserver } from "../../utils/observers";
 import { Validation } from "../functional/Validation";
 import { IconNameOrString } from "../icon/interfaces";
 import { isBrowser } from "../../utils/browser";
@@ -98,7 +97,7 @@ export class SegmentedControl
 
   @Watch("value")
   valueHandler(value: string): void {
-    const items = this.getItems();
+    const { items } = this;
     items.forEach((item) => (item.checked = item.value === value));
   }
 
@@ -110,7 +109,7 @@ export class SegmentedControl
   @Prop({ mutable: true }) selectedItem: HTMLCalciteSegmentedControlItemElement;
 
   @Watch("selectedItem")
-  protected handleSelectedItemChange<T extends HTMLCalciteSegmentedControlItemElement>(
+  handleSelectedItemChange<T extends HTMLCalciteSegmentedControlItemElement>(
     newItem: T,
     oldItem: T,
   ): void {
@@ -118,7 +117,7 @@ export class SegmentedControl
     if (newItem === oldItem) {
       return;
     }
-    const items = this.getItems();
+    const { items } = this;
     const match = items.filter((item) => item === newItem).pop();
 
     if (match) {
@@ -169,7 +168,6 @@ export class SegmentedControl
 
   componentWillLoad(): void {
     setUpLoadableComponent(this);
-    this.setUpItems();
   }
 
   componentDidLoad(): void {
@@ -180,15 +178,11 @@ export class SegmentedControl
   connectedCallback(): void {
     connectLabel(this);
     connectForm(this);
-    this.mutationObserver?.observe(this.el, { childList: true });
-
-    this.handleItemPropChange();
   }
 
   disconnectedCallback(): void {
     disconnectLabel(this);
     disconnectForm(this);
-    this.mutationObserver?.unobserve(this.el);
   }
 
   componentDidRender(): void {
@@ -204,7 +198,7 @@ export class SegmentedControl
           class={CSS.itemWrapper}
         >
           <InteractiveContainer disabled={this.disabled}>
-            <slot />
+            <slot onSlotchange={this.handleDefaultSlotChange} />
             <HiddenFormInputSlot component={this} />
           </InteractiveContainer>
         </div>
@@ -227,7 +221,7 @@ export class SegmentedControl
   //
   //--------------------------------------------------------------------------
 
-  protected handleClick = (event: MouseEvent): void => {
+  private handleClick = (event: MouseEvent): void => {
     if (this.disabled) {
       return;
     }
@@ -238,7 +232,7 @@ export class SegmentedControl
   };
 
   @Listen("calciteInternalSegmentedControlItemChange")
-  protected handleSelected(event: Event): void {
+  handleSelected(event: Event): void {
     event.preventDefault();
     const el = event.target as HTMLCalciteSegmentedControlItemElement;
     if (el.checked) {
@@ -268,7 +262,7 @@ export class SegmentedControl
       }
     }
 
-    const items = this.getItems();
+    const { items } = this;
     let selectedIndex = -1;
 
     items.forEach((item, index) => {
@@ -321,7 +315,7 @@ export class SegmentedControl
   async setFocus(): Promise<void> {
     await componentFocusable(this);
 
-    (this.selectedItem || this.getItems()[0])?.focus();
+    (this.selectedItem || this.items[0])?.focus();
   }
 
   //--------------------------------------------------------------------------
@@ -332,16 +326,22 @@ export class SegmentedControl
 
   @Element() el: HTMLCalciteSegmentedControlElement;
 
+  private items: HTMLCalciteSegmentedControlItemElement[] = [];
+
   labelEl: HTMLCalciteLabelElement;
 
   formEl: HTMLFormElement;
 
   defaultValue: SegmentedControl["value"];
 
-  private mutationObserver = createObserver("mutation", () => this.setUpItems());
+  //--------------------------------------------------------------------------
+  //
+  //  Private Methods
+  //
+  //--------------------------------------------------------------------------
 
   private handleItemPropChange(): void {
-    const items = this.getItems();
+    const { items } = this;
 
     items.forEach((item) => {
       item.appearance = this.appearance;
@@ -350,18 +350,32 @@ export class SegmentedControl
     });
   }
 
-  //--------------------------------------------------------------------------
-  //
-  //  Private Methods
-  //
-  //--------------------------------------------------------------------------
+  private handleSelectedItem(): void {
+    const { items } = this;
 
-  onLabelClick(): void {
-    this.setFocus();
+    const lastChecked = items.filter((item) => item.checked).pop();
+
+    if (lastChecked) {
+      this.selectItem(lastChecked);
+    } else if (items[0]) {
+      items[0].tabIndex = 0;
+    }
   }
 
-  private getItems(): HTMLCalciteSegmentedControlItemElement[] {
-    return Array.from(this.el.querySelectorAll("calcite-segmented-control-item"));
+  private handleDefaultSlotChange = (event: Event): void => {
+    const items = slotChangeGetAssignedElements(event).filter(
+      (el): el is HTMLCalciteSegmentedControlItemElement =>
+        el.matches("calcite-segmented-control-item"),
+    );
+
+    this.items = items;
+
+    this.handleSelectedItem();
+    this.handleItemPropChange();
+  };
+
+  onLabelClick(): void {
+    this.setFocus();
   }
 
   private selectItem(selected: HTMLCalciteSegmentedControlItemElement, emit = false): void {
@@ -369,7 +383,7 @@ export class SegmentedControl
       return;
     }
 
-    const items = this.getItems();
+    const { items } = this;
     let match: HTMLCalciteSegmentedControlItemElement = null;
 
     items.forEach((item) => {
@@ -395,15 +409,4 @@ export class SegmentedControl
       match.focus();
     }
   }
-
-  private setUpItems(): void {
-    const items = this.getItems();
-    const lastChecked = items.filter((item) => item.checked).pop();
-
-    if (lastChecked) {
-      this.selectItem(lastChecked);
-    } else if (items[0]) {
-      items[0].tabIndex = 0;
-    }
-  }
 }