diff --git a/extensions/microsoft-foundry/cli.ts b/extensions/microsoft-foundry/cli.ts
index 638247d28d8e..89859b4deb9d 100644
--- a/extensions/microsoft-foundry/cli.ts
+++ b/extensions/microsoft-foundry/cli.ts
@@ -144,7 +144,8 @@ export async function getAccessTokenResultAsync(
   ) as AzAccessToken;
 }
 
-const AZ_LOGIN_TIMEOUT_MS = 5 * 60 * 1000; // 5 minutes
+// Entra device codes default to 15 minutes; keep five minutes for az to finish.
+const AZ_LOGIN_TIMEOUT_MS = 20 * 60 * 1000;
 
 export async function azLoginDeviceCode(): Promise<void> {
   return azLoginDeviceCodeWithOptions({});
@@ -188,7 +189,7 @@ export async function azLoginDeviceCodeWithOptions(params: {
   appendOutput("stdout", decoders.stdout.end());
   appendOutput("stderr", decoders.stderr.end());
   if (result.termination === "timeout") {
-    throw new Error("az login timed out after 5 minutes");
+    throw new Error("az login timed out after 20 minutes");
   }
   if (result.code === 0) {
     return;
diff --git a/extensions/microsoft-foundry/index.test.ts b/extensions/microsoft-foundry/index.test.ts
index 0b6da87d0edf..636cc7f71ac8 100644
--- a/extensions/microsoft-foundry/index.test.ts
+++ b/extensions/microsoft-foundry/index.test.ts
@@ -2107,7 +2107,7 @@ describe("azLoginDeviceCodeWithOptions utf-8 chunk boundary", () => {
     expect(stderrWriteSpy).toHaveBeenCalledWith("😊");
   });
 
-  it("requests process-tree termination and rejects when az login exceeds 5 minutes", async () => {
+  it("allows post-auth work after the 15-minute device-code lifetime", async () => {
     runCommandWithTimeoutMock.mockResolvedValueOnce({
       stdout: "",
       stderr: "",
@@ -2120,13 +2120,13 @@ describe("azLoginDeviceCodeWithOptions utf-8 chunk boundary", () => {
 
     const err = await azLoginDeviceCodeWithOptions({}).catch((e: unknown) => e);
     expect(err).toBeInstanceOf(Error);
-    expect((err as Error).message).toBe("az login timed out after 5 minutes");
+    expect((err as Error).message).toBe("az login timed out after 20 minutes");
     expect(runCommandWithTimeoutMock).toHaveBeenCalledWith(
       ["az", "login", "--use-device-code"],
       expect.objectContaining({
         killProcessTree: true,
         outputCapture: "discard",
-        timeoutMs: 5 * 60 * 1000,
+        timeoutMs: 20 * 60 * 1000,
       }),
     );
   });