diff --git a/product.json b/product.json
index fe7d07a079b..af053a48660 100644
--- a/product.json
+++ b/product.json
@@ -116,6 +116,7 @@
 				"name": "Apple"
 			}
 		},
+		"providerExtensionId": "vscode.github-authentication",
 		"providerUriSetting": "github-enterprise.uri",
 		"providerScopes": [
 			[
diff --git a/src/vs/base/common/product.ts b/src/vs/base/common/product.ts
index 2602572ba07..8325d6789f0 100644
--- a/src/vs/base/common/product.ts
+++ b/src/vs/base/common/product.ts
@@ -360,6 +360,7 @@ export interface IDefaultChatAgent {
 		apple: { id: string; name: string };
 	};
 
+	readonly providerExtensionId: string;
 	readonly providerUriSetting: string;
 	readonly providerScopes: string[][];
 
diff --git a/src/vs/workbench/contrib/chat/browser/chatSetup/chatSetup.ts b/src/vs/workbench/contrib/chat/browser/chatSetup/chatSetup.ts
index 5a059de225b..868420e051d 100644
--- a/src/vs/workbench/contrib/chat/browser/chatSetup/chatSetup.ts
+++ b/src/vs/workbench/contrib/chat/browser/chatSetup/chatSetup.ts
@@ -4,11 +4,17 @@
  *--------------------------------------------------------------------------------------------*/
 
 import { ICommandService } from '../../../../../platform/commands/common/commands.js';
+import { ExtensionIdentifier } from '../../../../../platform/extensions/common/extensions.js';
+import { ILogService } from '../../../../../platform/log/common/log.js';
 import product from '../../../../../platform/product/common/product.js';
+import { localize } from '../../../../../nls.js';
+import { EnablementState } from '../../../../services/extensionManagement/common/extensionManagement.js';
+import { IExtensionsWorkbenchService } from '../../../extensions/common/extensions.js';
 
 const defaultChat = {
 	completionsRefreshTokenCommand: product.defaultChatAgent?.completionsRefreshTokenCommand ?? '',
 	chatRefreshTokenCommand: product.defaultChatAgent?.chatRefreshTokenCommand ?? '',
+	providerExtensionId: product.defaultChatAgent?.providerExtensionId ?? '',
 };
 
 export type InstallChatClassification = {
@@ -59,3 +65,44 @@ export function refreshTokens(commandService: ICommandService): void {
 	commandService.executeCommand(defaultChat.completionsRefreshTokenCommand);
 	commandService.executeCommand(defaultChat.chatRefreshTokenCommand);
 }
+
+/**
+ * Ensures the authentication provider extension is enabled.
+ * If the extension is found locally but disabled, it will be
+ * re-enabled and running extensions will be updated.
+ *
+ * @returns `true` if the extension was re-enabled, `false` otherwise.
+ */
+export async function maybeEnableAuthExtension(
+	extensionsWorkbenchService: IExtensionsWorkbenchService,
+	logService: ILogService
+): Promise<boolean> {
+	if (!defaultChat.providerExtensionId) {
+		return false;
+	}
+
+	const providerExtension = extensionsWorkbenchService.local.find(
+		e => ExtensionIdentifier.equals(e.identifier.id, defaultChat.providerExtensionId)
+	);
+
+	if (!providerExtension) {
+		return false;
+	}
+
+	if (
+		providerExtension.enablementState === EnablementState.DisabledGlobally ||
+		providerExtension.enablementState === EnablementState.DisabledWorkspace
+	) {
+		logService.info(`[chat setup] auth provider extension '${defaultChat.providerExtensionId}' is disabled, re-enabling it`);
+		try {
+			await extensionsWorkbenchService.setEnablement([providerExtension], EnablementState.EnabledGlobally);
+			await extensionsWorkbenchService.updateRunningExtensions(localize('enableAuthExtension', "Enabling GitHub Authentication"));
+			return true;
+		} catch (error) {
+			logService.error(`[chat setup] failed to re-enable auth provider extension '${defaultChat.providerExtensionId}'`, error);
+			return false;
+		}
+	}
+
+	return false;
+}
diff --git a/src/vs/workbench/contrib/chat/browser/chatSetup/chatSetupController.ts b/src/vs/workbench/contrib/chat/browser/chatSetup/chatSetupController.ts
index 0379543f996..eb5a4f427b9 100644
--- a/src/vs/workbench/contrib/chat/browser/chatSetup/chatSetupController.ts
+++ b/src/vs/workbench/contrib/chat/browser/chatSetup/chatSetupController.ts
@@ -28,7 +28,7 @@ import { IExtensionsWorkbenchService } from '../../../extensions/common/extensio
 import { ChatEntitlement, ChatEntitlementContext, ChatEntitlementRequests, isProUser } from '../../../../services/chat/common/chatEntitlementService.js';
 import { CHAT_OPEN_ACTION_ID } from '../actions/chatActions.js';
 import { ChatViewId, ChatViewContainerId } from '../chat.js';
-import { ChatSetupAnonymous, ChatSetupStep, ChatSetupResultValue, InstallChatEvent, InstallChatClassification, refreshTokens } from './chatSetup.js';
+import { ChatSetupAnonymous, ChatSetupStep, ChatSetupResultValue, InstallChatEvent, InstallChatClassification, refreshTokens, maybeEnableAuthExtension } from './chatSetup.js';
 import { IDefaultAccount } from '../../../../../base/common/defaultAccount.js';
 import { IDefaultAccountService } from '../../../../../platform/defaultAccount/common/defaultAccount.js';
 
@@ -153,6 +153,11 @@ export class ChatSetupController extends Disposable {
 	}
 
 	private async signIn(options: IChatSetupControllerOptions): Promise<{ defaultAccount: IDefaultAccount | undefined; entitlement: ChatEntitlement | undefined }> {
+		const authExtensionReEnabled = await maybeEnableAuthExtension(this.extensionsWorkbenchService, this.logService);
+		if (authExtensionReEnabled) {
+			refreshTokens(this.commandService);
+		}
+
 		let entitlements;
 		let defaultAccount;
 		try {
diff --git a/src/vs/workbench/contrib/chat/browser/chatSetup/chatSetupProviders.ts b/src/vs/workbench/contrib/chat/browser/chatSetup/chatSetupProviders.ts
index 14541ee5f4b..1ff128a1f67 100644
--- a/src/vs/workbench/contrib/chat/browser/chatSetup/chatSetupProviders.ts
+++ b/src/vs/workbench/contrib/chat/browser/chatSetup/chatSetupProviders.ts
@@ -47,13 +47,14 @@ import { ACTION_START as INLINE_CHAT_START } from '../../../inlineChat/common/in
 import { IPosition } from '../../../../../editor/common/core/position.js';
 import { IMarker, IMarkerService, MarkerSeverity } from '../../../../../platform/markers/common/markers.js';
 import { ChatSetupController } from './chatSetupController.js';
-import { ChatSetupAnonymous, ChatSetupStep, IChatSetupResult } from './chatSetup.js';
+import { ChatSetupAnonymous, ChatSetupStep, IChatSetupResult, maybeEnableAuthExtension, refreshTokens } from './chatSetup.js';
 import { ChatSetup } from './chatSetupRunner.js';
 import { chatViewsWelcomeRegistry } from '../viewsWelcome/chatViewsWelcome.js';
 import { CommandsRegistry, ICommandService } from '../../../../../platform/commands/common/commands.js';
 import { IDefaultAccountService } from '../../../../../platform/defaultAccount/common/defaultAccount.js';
 import { IHostService } from '../../../../services/host/browser/host.js';
 import { IOutputService } from '../../../../services/output/common/output.js';
+import { IExtensionsWorkbenchService } from '../../../extensions/common/extensions.js';
 
 const defaultChat = {
 	extensionId: product.defaultChatAgent?.extensionId ?? '',
@@ -197,6 +198,8 @@ export class SetupAgent extends Disposable implements IChatAgentImplementation {
 		@IViewsService private readonly viewsService: IViewsService,
 		@IContextKeyService private readonly contextKeyService: IContextKeyService,
 		@IOutputService private readonly outputService: IOutputService,
+		@IExtensionsWorkbenchService private readonly extensionsWorkbenchService: IExtensionsWorkbenchService,
+		@ICommandService private readonly commandService: ICommandService,
 	) {
 		super();
 
@@ -315,6 +318,15 @@ export class SetupAgent extends Disposable implements IChatAgentImplementation {
 	}
 
 	private async doForwardRequestToChatWhenReady(requestModel: IChatRequestModel, progress: (part: IChatProgress) => void, chatService: IChatService, languageModelsService: ILanguageModelsService, chatAgentService: IChatAgentService, chatWidgetService: IChatWidgetService, languageModelToolsService: ILanguageModelToolsService): Promise<void> {
+
+		// Ensure auth extension is enabled before waiting for chat readiness.
+		// This must run before the readiness event listeners are set up because
+		// updateRunningExtensions restarts all extension hosts.
+		const authExtensionReEnabled = await maybeEnableAuthExtension(this.extensionsWorkbenchService, this.logService);
+		if (authExtensionReEnabled) {
+			refreshTokens(this.commandService);
+		}
+
 		const widget = chatWidgetService.getWidgetBySessionResource(requestModel.session.sessionResource);
 		const modeInfo = widget?.input.currentModeInfo;