diff --git a/button/internal/button.ts b/button/internal/button.ts
index 501268dc307..a4c089d53f3 100644
--- a/button/internal/button.ts
+++ b/button/internal/button.ts
@@ -14,7 +14,6 @@ import {literal, html as staticHtml} from 'lit/static-html.js';
 
 import {ARIAMixinStrict} from '../../internal/aria/aria.js';
 import {requestUpdateOnAriaChange} from '../../internal/aria/delegate.js';
-import {internals} from '../../internal/controller/element-internals.js';
 import {
   dispatchActivationClick,
   isActivationClick,
@@ -24,11 +23,18 @@ import {
   FormSubmitterType,
   setupFormSubmitter,
 } from '../../internal/controller/form-submitter.js';
+import {
+  internals,
+  mixinElementInternals,
+} from '../../labs/behaviors/element-internals.js';
+
+// Separate variable needed for closure.
+const buttonBaseClass = mixinElementInternals(LitElement);
 
 /**
  * A button component.
  */
-export abstract class Button extends LitElement implements FormSubmitter {
+export abstract class Button extends buttonBaseClass implements FormSubmitter {
   static {
     requestUpdateOnAriaChange(Button);
     setupFormSubmitter(Button);
@@ -95,10 +101,6 @@ export abstract class Button extends LitElement implements FormSubmitter {
   @queryAssignedElements({slot: 'icon', flatten: true})
   private readonly assignedIcons!: HTMLElement[];
 
-  /** @private */
-  [internals] = (this as HTMLElement) /* needed for closure */
-    .attachInternals();
-
   constructor() {
     super();
     if (!isServer) {
diff --git a/chips/internal/chip-set.ts b/chips/internal/chip-set.ts
index c7ac6eeb866..8fa151f4357 100644
--- a/chips/internal/chip-set.ts
+++ b/chips/internal/chip-set.ts
@@ -8,8 +8,8 @@ import {html, isServer, LitElement} from 'lit';
 import {queryAssignedElements} from 'lit/decorators.js';
 
 import {
+  polyfillARIAMixin,
   polyfillElementInternalsAria,
-  setupHostAria,
 } from '../../internal/aria/aria.js';
 
 import {Chip} from './chip.js';
@@ -19,7 +19,7 @@ import {Chip} from './chip.js';
  */
 export class ChipSet extends LitElement {
   static {
-    setupHostAria(ChipSet, {focusable: false});
+    polyfillARIAMixin(ChipSet);
   }
 
   get chips() {
diff --git a/iconbutton/internal/icon-button.ts b/iconbutton/internal/icon-button.ts
index 9162480c704..02391d75a66 100644
--- a/iconbutton/internal/icon-button.ts
+++ b/iconbutton/internal/icon-button.ts
@@ -14,18 +14,24 @@ import {literal, html as staticHtml} from 'lit/static-html.js';
 
 import {ARIAMixinStrict} from '../../internal/aria/aria.js';
 import {requestUpdateOnAriaChange} from '../../internal/aria/delegate.js';
-import {internals} from '../../internal/controller/element-internals.js';
 import {
   FormSubmitter,
   FormSubmitterType,
   setupFormSubmitter,
 } from '../../internal/controller/form-submitter.js';
 import {isRtl} from '../../internal/controller/is-rtl.js';
+import {
+  internals,
+  mixinElementInternals,
+} from '../../labs/behaviors/element-internals.js';
 
 type LinkTarget = '_blank' | '_parent' | '_self' | '_top';
 
+// Separate variable needed for closure.
+const iconButtonBaseClass = mixinElementInternals(LitElement);
+
 // tslint:disable-next-line:enforce-comments-on-exported-symbols
-export class IconButton extends LitElement implements FormSubmitter {
+export class IconButton extends iconButtonBaseClass implements FormSubmitter {
   static {
     requestUpdateOnAriaChange(IconButton);
     setupFormSubmitter(IconButton);
@@ -106,10 +112,6 @@ export class IconButton extends LitElement implements FormSubmitter {
 
   @state() private flipIcon = isRtl(this, this.flipIconInRtl);
 
-  /** @private */
-  [internals] = (this as HTMLElement) /* needed for closure */
-    .attachInternals();
-
   /**
    * Link buttons cannot be disabled.
    */
diff --git a/internal/aria/aria.ts b/internal/aria/aria.ts
index 64828cb694d..b5c1be4542a 100644
--- a/internal/aria/aria.ts
+++ b/internal/aria/aria.ts
@@ -295,37 +295,11 @@ export type ARIARole =
   | 'doc-toc';
 
 /**
- * Enables a host custom element to be the target for aria roles and attributes.
- * Components should set the `elementInternals.role` property.
- *
- * By default, aria components are tab focusable. Provide a `focusable: false`
- * option for components that should not be tab focusable, such as
- * `role="listbox"`.
- *
- * This function will also polyfill aria `ElementInternals` properties for
- * Firefox.
+ * This function will polyfill `ARIAMixin` properties for Firefox.
  *
  * @param ctor The `ReactiveElement` constructor to set up.
- * @param options Options to configure the element's host aria.
  */
-export function setupHostAria(
-  ctor: typeof ReactiveElement,
-  {focusable}: SetupHostAriaOptions = {},
-) {
-  if (focusable !== false) {
-    ctor.addInitializer((host) => {
-      host.addController({
-        hostConnected() {
-          if (host.hasAttribute('tabindex')) {
-            return;
-          }
-
-          host.tabIndex = 0;
-        },
-      });
-    });
-  }
-
+export function polyfillARIAMixin(ctor: typeof ReactiveElement) {
   if (isServer || 'role' in Element.prototype) {
     return;
   }
@@ -341,20 +315,6 @@ export function setupHostAria(
   ctor.createProperty('role', {reflect: true});
 }
 
-/**
- * Options for setting up a host element as an aria target.
- */
-export interface SetupHostAriaOptions {
-  /**
-   * Whether or not the element can be focused with the tab key. Defaults to
-   * true.
-   *
-   * Set this to false for aria roles that should not be tab focusable, such as
-   * `role="listbox"`.
-   */
-  focusable?: boolean;
-}
-
 /**
  * Polyfills an element and its `ElementInternals` to support `ARIAMixin`
  * properties on internals. This is needed for Firefox.
diff --git a/internal/aria/aria_test.ts b/internal/aria/aria_test.ts
index 6a40249c4de..efa2dafde81 100644
--- a/internal/aria/aria_test.ts
+++ b/internal/aria/aria_test.ts
@@ -13,8 +13,8 @@ import {
   ARIAProperty,
   ariaPropertyToAttribute,
   isAriaAttribute,
+  polyfillARIAMixin,
   polyfillElementInternalsAria,
-  setupHostAria,
 } from './aria.js';
 
 describe('aria', () => {
@@ -52,11 +52,11 @@ describe('aria', () => {
     });
   });
 
-  describe('setupHostAria()', () => {
+  describe('polyfillARIAMixin()', () => {
     @customElement('test-setup-aria-host')
     class TestElement extends LitElement {
       static {
-        setupHostAria(TestElement);
+        polyfillARIAMixin(TestElement);
       }
 
       override render() {
@@ -64,67 +64,28 @@ describe('aria', () => {
       }
     }
 
-    it('should not hydrate tabindex attribute on creation', () => {
+    it('should reflect ARIAMixin properties to attributes', async () => {
       const element = new TestElement();
-      expect(element.hasAttribute('tabindex'))
-        .withContext('has tabindex attribute')
-        .toBeFalse();
-    });
-
-    it('should set tabindex="0" on element once connected', () => {
-      const element = new TestElement();
-      document.body.appendChild(element);
-      expect(element.getAttribute('tabindex'))
-        .withContext('tabindex attribute value')
-        .toEqual('0');
-
-      element.remove();
-    });
-
-    it('should not set tabindex on connected if one already exists', () => {
-      const element = new TestElement();
-      element.tabIndex = -1;
       document.body.appendChild(element);
-      expect(element.getAttribute('tabindex'))
-        .withContext('tabindex attribute value')
-        .toEqual('-1');
-
+      element.role = 'button';
+      element.ariaLabel = 'Foo';
+      await element.updateComplete;
+      expect(element.getAttribute('role'))
+        .withContext('role attribute value')
+        .toEqual('button');
+
+      expect(element.getAttribute('aria-label'))
+        .withContext('aria-label attribute value')
+        .toEqual('Foo');
       element.remove();
     });
-
-    it('should not change tabindex if disconnected and reconnected', () => {
-      const element = new TestElement();
-      document.body.appendChild(element);
-      element.tabIndex = -1;
-      element.remove();
-      document.body.appendChild(element);
-      expect(element.getAttribute('tabindex'))
-        .withContext('tabindex attribute value')
-        .toEqual('-1');
-    });
-
-    if (!('role' in Element.prototype)) {
-      describe('polyfill', () => {
-        it('should hydrate aria attributes when ARIAMixin is not supported', async () => {
-          const element = new TestElement();
-          document.body.appendChild(element);
-          element.role = 'button';
-          await element.updateComplete;
-          expect(element.getAttribute('role'))
-            .withContext('role attribute value')
-            .toEqual('button');
-
-          element.remove();
-        });
-      });
-    }
   });
 
   describe('polyfillElementInternalsAria()', () => {
     @customElement('test-polyfill-element-internals-aria')
     class TestElement extends LitElement {
       static {
-        setupHostAria(TestElement);
+        polyfillARIAMixin(TestElement);
       }
 
       internals = polyfillElementInternalsAria(this, this.attachInternals());
diff --git a/internal/controller/element-internals.ts b/internal/controller/element-internals.ts
deleted file mode 100644
index 3cdc3ca59c9..00000000000
--- a/internal/controller/element-internals.ts
+++ /dev/null
@@ -1,37 +0,0 @@
-/**
- * @license
- * Copyright 2023 Google LLC
- * SPDX-License-Identifier: Apache-2.0
- */
-
-/**
- * A unique symbol used for protected access to an instance's
- * `ElementInternals`.
- *
- * @example
- * ```ts
- * class MyElement extends LitElement {
- *   static formAssociated = true;
- *
- *   [internals] = this.attachInternals();
- * }
- *
- * function getForm(element: MyElement) {
- *   return element[internals].form;
- * }
- * ```
- */
-export const internals = Symbol('internals');
-
-/**
- * An instance with `ElementInternals`.
- *
- * Use this when protected access is needed for an instance's `ElementInternals`
- * from other files. A unique symbol is used to access the internals.
- */
-export interface WithInternals {
-  /**
-   * An instance's `ElementInternals`.
-   */
-  [internals]: ElementInternals;
-}
diff --git a/internal/controller/form-submitter.ts b/internal/controller/form-submitter.ts
index 221c64d28f1..bb99101ca59 100644
--- a/internal/controller/form-submitter.ts
+++ b/internal/controller/form-submitter.ts
@@ -6,7 +6,10 @@
 
 import {isServer, ReactiveElement} from 'lit';
 
-import {internals, WithInternals} from './element-internals.js';
+import {
+  internals,
+  WithElementInternals,
+} from '../../labs/behaviors/element-internals.js';
 
 /**
  * A string indicating the form submission behavior of the element.
@@ -23,7 +26,7 @@ export type FormSubmitterType = 'button' | 'submit' | 'reset';
  * An element that can submit or reset a `<form>`, similar to
  * `<button type="submit">`.
  */
-export interface FormSubmitter extends ReactiveElement, WithInternals {
+export interface FormSubmitter extends ReactiveElement, WithElementInternals {
   /**
    * A string indicating the form submission behavior of the element.
    *
diff --git a/internal/controller/form-submitter_test.ts b/internal/controller/form-submitter_test.ts
index 14aa439f1ee..80cd07ceee1 100644
--- a/internal/controller/form-submitter_test.ts
+++ b/internal/controller/form-submitter_test.ts
@@ -9,10 +9,9 @@
 import {html, LitElement} from 'lit';
 import {customElement, property} from 'lit/decorators.js';
 
+import {mixinElementInternals} from '../../labs/behaviors/element-internals.js';
 import {Environment} from '../../testing/environment.js';
 import {Harness} from '../../testing/harness.js';
-
-import {internals} from './element-internals.js';
 import {FormSubmitterType, setupFormSubmitter} from './form-submitter.js';
 
 declare global {
@@ -22,7 +21,7 @@ declare global {
 }
 
 @customElement('test-form-submitter-button')
-class FormSubmitterButton extends LitElement {
+class FormSubmitterButton extends mixinElementInternals(LitElement) {
   static {
     setupFormSubmitter(FormSubmitterButton);
   }
@@ -32,8 +31,6 @@ class FormSubmitterButton extends LitElement {
   type: FormSubmitterType = 'submit';
   @property({reflect: true}) name = '';
   value = '';
-
-  [internals] = this.attachInternals();
 }
 
 describe('setupFormSubmitter()', () => {
diff --git a/labs/behaviors/element-internals.ts b/labs/behaviors/element-internals.ts
new file mode 100644
index 00000000000..f583367c631
--- /dev/null
+++ b/labs/behaviors/element-internals.ts
@@ -0,0 +1,62 @@
+/**
+ * @license
+ * Copyright 2023 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import {LitElement} from 'lit';
+
+import {MixinBase, MixinReturn} from './mixin.js';
+
+/**
+ * A unique symbol used for protected access to an instance's
+ * `ElementInternals`.
+ *
+ * @example
+ * ```ts
+ * class MyElement extends mixinElementInternals(LitElement) {
+ *   constructor() {
+ *     super();
+ *     this[internals].role = 'button';
+ *   }
+ * }
+ * ```
+ */
+export const internals = Symbol('internals');
+
+/**
+ * An instance with an `internals` symbol property for the component's
+ * `ElementInternals`.
+ *
+ * Use this when protected access is needed for an instance's `ElementInternals`
+ * from other files. A unique symbol is used to access the internals.
+ */
+export interface WithElementInternals {
+  /**
+   * An instance's `ElementInternals`.
+   */
+  [internals]: ElementInternals;
+}
+
+/**
+ * Mixes in an attached `ElementInternals` instance.
+ *
+ * This mixin is only needed when other shared code needs access to a
+ * component's `ElementInternals`, such as form-associated mixins.
+ *
+ * @param base The class to mix functionality into.
+ * @return The provided class with `WithElementInternals` mixed in.
+ */
+export function mixinElementInternals<T extends MixinBase<LitElement>>(
+  base: T,
+): MixinReturn<T, WithElementInternals> {
+  abstract class WithElementInternalsElement
+    extends base
+    implements WithElementInternals
+  {
+    // Cast needed for closure
+    [internals] = (this as HTMLElement).attachInternals();
+  }
+
+  return WithElementInternalsElement;
+}
diff --git a/labs/behaviors/element-internals_test.ts b/labs/behaviors/element-internals_test.ts
new file mode 100644
index 00000000000..9a9a292cfcb
--- /dev/null
+++ b/labs/behaviors/element-internals_test.ts
@@ -0,0 +1,37 @@
+/**
+ * @license
+ * Copyright 2023 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+// import 'jasmine'; (google3-only)
+
+import {html, LitElement} from 'lit';
+import {customElement} from 'lit/decorators.js';
+
+import {Environment} from '../../testing/environment.js';
+
+import {internals, mixinElementInternals} from './element-internals.js';
+
+describe('mixinElementInternals()', () => {
+  @customElement('test-element-internals')
+  class TestElementInternals extends mixinElementInternals(LitElement) {}
+
+  const env = new Environment();
+
+  async function setupTest() {
+    const root = env.render(
+      html`<test-element-internals></test-element-internals>`,
+    );
+    const element = root.querySelector(
+      'test-element-internals',
+    ) as TestElementInternals;
+    await env.waitForStability();
+    return element;
+  }
+
+  it('should provide an `ElementInternals` instance', async () => {
+    const element = await setupTest();
+    expect(element[internals]).toBeInstanceOf(ElementInternals);
+  });
+});
diff --git a/list/internal/list.ts b/list/internal/list.ts
index 06338d10555..bf0ce07c3d4 100644
--- a/list/internal/list.ts
+++ b/list/internal/list.ts
@@ -8,8 +8,8 @@ import {html, isServer, LitElement} from 'lit';
 import {queryAssignedElements} from 'lit/decorators.js';
 
 import {
+  polyfillARIAMixin,
   polyfillElementInternalsAria,
-  setupHostAria,
 } from '../../internal/aria/aria.js';
 
 import {ListController, NavigableKeys} from './list-controller.js';
@@ -24,7 +24,7 @@ interface ListItem extends SharedListItem {
 // tslint:disable-next-line:enforce-comments-on-exported-symbols
 export class List extends LitElement {
   static {
-    setupHostAria(List, {focusable: false});
+    polyfillARIAMixin(List);
   }
 
   /**
diff --git a/menu/internal/menu.ts b/menu/internal/menu.ts
index a50015f4d8c..eb0fa449a8b 100644
--- a/menu/internal/menu.ts
+++ b/menu/internal/menu.ts
@@ -13,10 +13,11 @@ import {classMap} from 'lit/directives/class-map.js';
 import {styleMap} from 'lit/directives/style-map.js';
 
 import {
+  polyfillARIAMixin,
   polyfillElementInternalsAria,
-  setupHostAria,
 } from '../../internal/aria/aria.js';
 import {createAnimationSignal, EASING} from '../../internal/motion/animation.js';
+import {isFocusable, mixinFocusable} from '../../labs/behaviors/focusable.js';
 import {
   ListController,
   NavigableKeys,
@@ -83,16 +84,18 @@ function getFocusedElement(
   return activeEl;
 }
 
+// Separate variable needed for closure.
+const menuBaseClass = mixinFocusable(LitElement);
+
 /**
  * @fires opening Fired before the opening animation begins
  * @fires opened Fired once the menu is open, after any animations
  * @fires closing Fired before the closing animation begins
  * @fires closed Fired once the menu is closed, after any animations
  */
-export abstract class Menu extends LitElement {
+export abstract class Menu extends menuBaseClass {
   static {
-    // We want to manage tabindex ourselves.
-    setupHostAria(Menu, {focusable: false});
+    polyfillARIAMixin(Menu);
   }
 
   @query('.menu') private readonly surfaceEl!: HTMLElement | null;
@@ -325,6 +328,8 @@ export abstract class Menu extends LitElement {
 
   constructor() {
     super();
+    // Menus are not focusable by default.
+    this[isFocusable] = false;
     if (!isServer) {
       this.internals.role = 'menu';
       this.addEventListener('keydown', this.handleKeydown);
diff --git a/radio/internal/radio.ts b/radio/internal/radio.ts
index 8a7e5816122..dd7db1d3377 100644
--- a/radio/internal/radio.ts
+++ b/radio/internal/radio.ts
@@ -12,16 +12,20 @@ import {property} from 'lit/decorators.js';
 import {classMap} from 'lit/directives/class-map.js';
 
 import {
+  polyfillARIAMixin,
   polyfillElementInternalsAria,
-  setupHostAria,
 } from '../../internal/aria/aria.js';
 import {isActivationClick} from '../../internal/controller/events.js';
+import {mixinFocusable} from '../../labs/behaviors/focusable.js';
 
 import {SingleSelectionController} from './single-selection-controller.js';
 
 const CHECKED = Symbol('checked');
 let maskId = 0;
 
+// Separate variable needed for closure.
+const radioBaseClass = mixinFocusable(LitElement);
+
 /**
  * A radio component.
  *
@@ -30,9 +34,9 @@ let maskId = 0;
  * @fires change Dispatched when the value changes from user interaction.
  * --bubbles --composed
  */
-export class Radio extends LitElement {
+export class Radio extends radioBaseClass {
   static {
-    setupHostAria(Radio);
+    polyfillARIAMixin(Radio);
   }
 
   /** @nocollapse */
@@ -116,7 +120,7 @@ export class Radio extends LitElement {
   }
 
   protected override render() {
-    const classes = {checked: this.checked};
+    const classes = {'checked': this.checked};
     return html`
       <div class="container ${classMap(classes)}" aria-hidden="true">
         <md-ripple
diff --git a/tabs/internal/tab.ts b/tabs/internal/tab.ts
index 5438f9af8fc..f7a049e0675 100644
--- a/tabs/internal/tab.ts
+++ b/tabs/internal/tab.ts
@@ -19,10 +19,11 @@ import {
 import {classMap} from 'lit/directives/class-map.js';
 
 import {
+  polyfillARIAMixin,
   polyfillElementInternalsAria,
-  setupHostAria,
 } from '../../internal/aria/aria.js';
 import {EASING} from '../../internal/motion/animation.js';
+import {mixinFocusable} from '../../labs/behaviors/focusable.js';
 
 /**
  * Symbol for tabs to use to animate their indicators based off another tab's
@@ -36,12 +37,15 @@ const INDICATOR = Symbol('indicator');
  */
 export const ANIMATE_INDICATOR = Symbol('animateIndicator');
 
+// Separate variable needed for closure.
+const tabBaseClass = mixinFocusable(LitElement);
+
 /**
  * Tab component.
  */
-export class Tab extends LitElement {
+export class Tab extends tabBaseClass {
   static {
-    setupHostAria(Tab);
+    polyfillARIAMixin(Tab);
   }
 
   /**
diff --git a/tabs/internal/tabs.ts b/tabs/internal/tabs.ts
index 23d08a2a88e..ce9740729f3 100644
--- a/tabs/internal/tabs.ts
+++ b/tabs/internal/tabs.ts
@@ -10,8 +10,8 @@ import {html, isServer, LitElement} from 'lit';
 import {property, query, queryAssignedElements} from 'lit/decorators.js';
 
 import {
+  polyfillARIAMixin,
   polyfillElementInternalsAria,
-  setupHostAria,
 } from '../../internal/aria/aria.js';
 
 import {ANIMATE_INDICATOR, Tab} from './tab.js';
@@ -42,7 +42,7 @@ import {ANIMATE_INDICATOR, Tab} from './tab.js';
  */
 export class Tabs extends LitElement {
   static {
-    setupHostAria(Tabs, {focusable: false});
+    polyfillARIAMixin(Tabs);
   }
 
   /**