diff --git a/common/api-review/auth.api.md b/common/api-review/auth.api.md
index ef28f329f56..4c1a00d154b 100644
--- a/common/api-review/auth.api.md
+++ b/common/api-review/auth.api.md
@@ -88,6 +88,7 @@ export interface Auth {
     readonly config: Config;
     readonly currentUser: User | null;
     readonly emulatorConfig: EmulatorConfig | null;
+    readonly firebaseToken: FirebaseToken | null;
     languageCode: string | null;
     readonly name: string;
     onAuthStateChanged(nextOrObserver: NextOrObserver<User | null>, error?: ErrorFn, completed?: CompleteFn): Unsubscribe;
@@ -364,7 +365,7 @@ export interface EmulatorConfig {
 
 export { ErrorFn }
 
-// @public (undocumented)
+// @public
 export function exchangeToken(auth: Auth, idpConfigId: string, customToken: string): Promise<string>;
 
 // Warning: (ae-forgotten-export) The symbol "BaseOAuthProvider" needs to be exported by the entry point index.d.ts
@@ -388,6 +389,14 @@ export const FactorId: {
 // @public
 export function fetchSignInMethodsForEmail(auth: Auth, email: string): Promise<string[]>;
 
+// @public (undocumented)
+export interface FirebaseToken {
+    // (undocumented)
+    readonly expirationTime: number;
+    // (undocumented)
+    readonly token: string;
+}
+
 // @public
 export function getAdditionalUserInfo(userCredential: UserCredential): AdditionalUserInfo | null;
 
diff --git a/packages/auth/src/core/auth/auth_impl.ts b/packages/auth/src/core/auth/auth_impl.ts
index 1c377b37332..2651fe43af9 100644
--- a/packages/auth/src/core/auth/auth_impl.ts
+++ b/packages/auth/src/core/auth/auth_impl.ts
@@ -460,9 +460,7 @@ export class AuthImpl implements AuthInternal, _FirebaseService {
   async _updateFirebaseToken(
     firebaseToken: FirebaseToken | null
   ): Promise<void> {
-    if (firebaseToken) {
-      this.firebaseToken = firebaseToken;
-    }
+    this.firebaseToken = firebaseToken;
   }
 
   async signOut(): Promise<void> {
diff --git a/packages/auth/src/core/auth/firebase_internal.test.ts b/packages/auth/src/core/auth/firebase_internal.test.ts
index ff5b94b3f4f..4213d720385 100644
--- a/packages/auth/src/core/auth/firebase_internal.test.ts
+++ b/packages/auth/src/core/auth/firebase_internal.test.ts
@@ -18,13 +18,19 @@
 import { FirebaseError } from '@firebase/util';
 import { expect, use } from 'chai';
 import * as sinon from 'sinon';
+import sinonChai from 'sinon-chai';
 import chaiAsPromised from 'chai-as-promised';
 
-import { testAuth, testUser } from '../../../test/helpers/mock_auth';
+import {
+  regionalTestAuth,
+  testAuth,
+  testUser
+} from '../../../test/helpers/mock_auth';
 import { AuthInternal } from '../../model/auth';
 import { UserInternal } from '../../model/user';
 import { AuthInterop } from './firebase_internal';
 
+use(sinonChai);
 use(chaiAsPromised);
 
 describe('core/auth/firebase_internal', () => {
@@ -37,6 +43,9 @@ describe('core/auth/firebase_internal', () => {
 
   afterEach(() => {
     sinon.restore();
+    delete (auth as unknown as Record<string, unknown>)[
+      '_initializationPromise'
+    ];
   });
 
   context('getUid', () => {
@@ -215,3 +224,74 @@ describe('core/auth/firebase_internal', () => {
     });
   });
 });
+
+describe('core/auth/firebase_internal - Regional Firebase Auth', () => {
+  let regionalAuth: AuthInternal;
+  let regionalAuthInternal: AuthInterop;
+  let now: number;
+  beforeEach(async () => {
+    regionalAuth = await regionalTestAuth();
+    regionalAuthInternal = new AuthInterop(regionalAuth);
+    now = Date.now();
+    sinon.stub(Date, 'now').returns(now);
+  });
+
+  afterEach(() => {
+    sinon.restore();
+  });
+
+  context('getFirebaseToken', () => {
+    it('returns null if firebase token is undefined', async () => {
+      expect(await regionalAuthInternal.getToken()).to.be.null;
+    });
+
+    it('returns the id token correctly', async () => {
+      await regionalAuth._updateFirebaseToken({
+        token: 'access-token',
+        expirationTime: now + 300_000
+      });
+      expect(await regionalAuthInternal.getToken()).to.eql({
+        accessToken: 'access-token'
+      });
+    });
+
+    it('logs out the the id token expires in next 30 seconds', async () => {
+      expect(await regionalAuthInternal.getToken()).to.be.null;
+    });
+
+    it('logs out if token has expired', async () => {
+      await regionalAuth._updateFirebaseToken({
+        token: 'access-token',
+        expirationTime: now - 5_000
+      });
+      expect(await regionalAuthInternal.getToken()).to.null;
+      expect(regionalAuth.firebaseToken).to.null;
+    });
+
+    it('logs out if token is expiring in next 5 seconds', async () => {
+      await regionalAuth._updateFirebaseToken({
+        token: 'access-token',
+        expirationTime: now + 5_000
+      });
+      expect(await regionalAuthInternal.getToken()).to.null;
+      expect(regionalAuth.firebaseToken).to.null;
+    });
+
+    it('logs warning if getToken is called with forceRefresh true', async () => {
+      sinon.stub(console, 'warn');
+      await regionalAuth._updateFirebaseToken({
+        token: 'access-token',
+        expirationTime: now + 300_000
+      });
+      expect(await regionalAuthInternal.getToken(true)).to.eql({
+        accessToken: 'access-token'
+      });
+      expect(console.warn).to.have.been.calledWith(
+        sinon.match.string,
+        sinon.match(
+          /Refresh token is not a valid operation for Regional Auth instance initialized\./
+        )
+      );
+    });
+  });
+});
diff --git a/packages/auth/src/core/auth/firebase_internal.ts b/packages/auth/src/core/auth/firebase_internal.ts
index 4fad0754375..caf06c49f6a 100644
--- a/packages/auth/src/core/auth/firebase_internal.ts
+++ b/packages/auth/src/core/auth/firebase_internal.ts
@@ -22,12 +22,14 @@ import { AuthInternal } from '../../model/auth';
 import { UserInternal } from '../../model/user';
 import { _assert } from '../util/assert';
 import { AuthErrorCode } from '../errors';
+import { _logWarn } from '../util/log';
 
 interface TokenListener {
   (tok: string | null): unknown;
 }
 
 export class AuthInterop implements FirebaseAuthInternal {
+  private readonly TOKEN_EXPIRATION_BUFFER = 30_000;
   private readonly internalListeners: Map<TokenListener, Unsubscribe> =
     new Map();
 
@@ -43,6 +45,14 @@ export class AuthInterop implements FirebaseAuthInternal {
   ): Promise<{ accessToken: string } | null> {
     this.assertAuthConfigured();
     await this.auth._initializationPromise;
+    if (this.auth.tenantConfig) {
+      if (forceRefresh) {
+        _logWarn(
+          'Refresh token is not a valid operation for Regional Auth instance initialized.'
+        );
+      }
+      return this.getTokenForRegionalAuth();
+    }
     if (!this.auth.currentUser) {
       return null;
     }
@@ -92,4 +102,24 @@ export class AuthInterop implements FirebaseAuthInternal {
       this.auth._stopProactiveRefresh();
     }
   }
+
+  private async getTokenForRegionalAuth(): Promise<{
+    accessToken: string;
+  } | null> {
+    if (!this.auth.firebaseToken) {
+      return null;
+    }
+
+    if (
+      !this.auth.firebaseToken.expirationTime ||
+      Date.now() >
+        this.auth.firebaseToken.expirationTime - this.TOKEN_EXPIRATION_BUFFER
+    ) {
+      await this.auth._updateFirebaseToken(null);
+      return null;
+    }
+
+    const accessToken = await this.auth.firebaseToken.token;
+    return { accessToken };
+  }
 }
diff --git a/packages/auth/test/helpers/mock_auth.ts b/packages/auth/test/helpers/mock_auth.ts
index 68e155a88f4..dee18047fde 100644
--- a/packages/auth/test/helpers/mock_auth.ts
+++ b/packages/auth/test/helpers/mock_auth.ts
@@ -118,7 +118,11 @@ export async function testAuth(
   return auth;
 }
 
-export async function regionalTestAuth(): Promise<TestAuth> {
+export async function regionalTestAuth(
+  popupRedirectResolver?: PopupRedirectResolver,
+  persistence = new MockPersistenceLayer(),
+  skipAwaitOnInit?: boolean
+): Promise<TestAuth> {
   const tenantConfig = { 'location': 'us', 'tenantId': 'tenant-1' };
   const auth: TestAuth = new AuthImpl(
     FAKE_APP,
@@ -135,6 +139,15 @@ export async function regionalTestAuth(): Promise<TestAuth> {
     },
     tenantConfig
   ) as TestAuth;
+  if (skipAwaitOnInit) {
+    // This is used to verify scenarios where auth flows (like signInWithRedirect) are invoked before auth is fully initialized.
+    // eslint-disable-next-line @typescript-eslint/no-floating-promises
+    auth._initializeWithPersistence([persistence], popupRedirectResolver);
+  } else {
+    await auth._initializeWithPersistence([persistence], popupRedirectResolver);
+  }
+  auth.persistenceLayer = persistence;
+  auth.settings.appVerificationDisabledForTesting = true;
   return auth;
 }