diff --git a/CHANGELOG.md b/CHANGELOG.md
index 632499b..6de0e5d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,10 @@
 # Changelog
 
+## 0.10.28 (Preview)
+
+### Deprecated
+- **This extension has moved to the official Microsoft extension** — `dotutils.binlog-analyzer` is now published as [`ms-dotnettools.msbuild-binlog-analyzer`](https://marketplace.visualstudio.com/items?itemName=ms-dotnettools.msbuild-binlog-analyzer) ("MSBuild Binlog Analyzer for VS Code"). This `dotutils` build is deprecated and will no longer be updated. It now nudges users to migrate with a one-time blocking dialog (offering to install the official extension and uninstall this one) plus a persistent status-bar warning that remains until you migrate or opt out; the notice stays silent once the official extension is installed. The README and Marketplace listing point to the replacement.
+
 ## 0.10.27 (Preview)
 
 ### Added
diff --git a/README.md b/README.md
index b90816c..a3b1544 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,13 @@
 # MSBuild Binlog Analyzer for VS Code
 
-[![VS Marketplace](https://img.shields.io/visual-studio-marketplace/v/dotutils.binlog-analyzer?label=VS%20Marketplace&color=blue)](https://marketplace.visualstudio.com/items?itemName=dotutils.binlog-analyzer)
-[![Installs](https://img.shields.io/visual-studio-marketplace/i/dotutils.binlog-analyzer)](https://marketplace.visualstudio.com/items?itemName=dotutils.binlog-analyzer)
+> # ⚠️ This extension is deprecated
+>
+> **`dotutils.binlog-analyzer` has moved to the official Microsoft extension:**
+> **[MSBuild Binlog Analyzer for VS Code (`ms-dotnettools.msbuild-binlog-analyzer`)](https://marketplace.visualstudio.com/items?itemName=ms-dotnettools.msbuild-binlog-analyzer)**
+>
+> This `dotutils` version is no longer maintained and will not receive updates.
+> Please install the official extension and uninstall this one. VS Code will
+> also prompt you to migrate automatically.
 
 Analyze MSBuild binary logs (`.binlog`) with **GitHub Copilot Chat** and **MCP tools** — right from VS Code.
 
diff --git a/package.json b/package.json
index 1052b77..260652d 100644
--- a/package.json
+++ b/package.json
@@ -1,8 +1,8 @@
 {
   "name": "binlog-analyzer",
-  "displayName": "MSBuild Binlog Analyzer",
-  "description": "Analyze MSBuild binary logs with Copilot Chat and MCP tools",
-  "version": "0.10.27",
+  "displayName": "MSBuild Binlog Analyzer (DEPRECATED \u2014 use ms-dotnettools.msbuild-binlog-analyzer)",
+  "description": "DEPRECATED: install the official \"MSBuild Binlog Analyzer for VS Code\" (ms-dotnettools.msbuild-binlog-analyzer) instead. Analyze MSBuild binary logs with Copilot Chat and MCP tools.",
+  "version": "0.10.28",
   "preview": true,
   "publisher": "dotutils",
   "license": "MIT",
diff --git a/src/deprecationNotice.ts b/src/deprecationNotice.ts
new file mode 100644
index 0000000..7fed2de
--- /dev/null
+++ b/src/deprecationNotice.ts
@@ -0,0 +1,84 @@
+import * as vscode from 'vscode';
+
+/**
+ * This "dotutils" extension is deprecated in favor of the official Microsoft
+ * extension. A single transient toast is too easy to dismiss, so we use two
+ * layers that are hard to miss but not obnoxious:
+ *   1. A blocking modal shown exactly once (Escape/Cancel only defers it to the
+ *      next activation — it is never treated as a permanent dismissal).
+ *   2. A persistent status-bar warning that stays until the user migrates or
+ *      explicitly opts out, and re-opens the migration prompt on click.
+ * Everything is best-effort and must never block or break activation.
+ */
+const NEW_EXTENSION_ID = 'ms-dotnettools.msbuild-binlog-analyzer';
+const OLD_EXTENSION_ID = 'dotutils.binlog-analyzer';
+const MIGRATE_COMMAND = 'binlog.showDeprecationMigration';
+const SUPPRESS_KEY = 'binlog.deprecationNoticeSuppressed';
+const MODAL_SHOWN_KEY = 'binlog.deprecationModalShown';
+
+export function registerDeprecationNotice(context: vscode.ExtensionContext): void {
+    try {
+        // Already migrated — the official extension is installed, so stay quiet.
+        if (vscode.extensions.getExtension(NEW_EXTENSION_ID)) {
+            return;
+        }
+        if (context.globalState.get<boolean>(SUPPRESS_KEY)) {
+            return;
+        }
+
+        // Persistent, always-visible reminder that survives dismissing the dialog.
+        const status = vscode.window.createStatusBarItem(vscode.StatusBarAlignment.Left, -100);
+        status.text = '$(warning) Binlog Analyzer deprecated';
+        status.tooltip = 'This extension has moved to ms-dotnettools.msbuild-binlog-analyzer. Click to migrate.';
+        status.backgroundColor = new vscode.ThemeColor('statusBarItem.warningBackground');
+        status.command = MIGRATE_COMMAND;
+        status.show();
+        context.subscriptions.push(status);
+
+        const migrate = async (modal: boolean): Promise<void> => {
+            try {
+                const install = 'Install new extension';
+                const dismiss = "Don't show again";
+                const choice = await vscode.window.showWarningMessage(
+                    'MSBuild Binlog Analyzer has moved to the official Microsoft extension ' +
+                    '"MSBuild Binlog Analyzer for VS Code" (ms-dotnettools.msbuild-binlog-analyzer). ' +
+                    'This "dotutils" version is deprecated and will no longer be updated. ' +
+                    'Please install the official extension to keep getting updates.',
+                    { modal },
+                    install, dismiss);
+
+                if (choice === install) {
+                    await vscode.commands.executeCommand('workbench.extensions.installExtension', NEW_EXTENSION_ID);
+                    status.hide();
+                    const uninstall = 'Uninstall old & reload';
+                    const next = await vscode.window.showInformationMessage(
+                        'The official extension is installed. Uninstall this deprecated version and reload to finish migrating?',
+                        uninstall, 'Later');
+                    if (next === uninstall) {
+                        await vscode.commands.executeCommand('workbench.extensions.uninstallExtension', OLD_EXTENSION_ID);
+                        await vscode.commands.executeCommand('workbench.action.reloadWindow');
+                    }
+                } else if (choice === dismiss) {
+                    await context.globalState.update(SUPPRESS_KEY, true);
+                    status.hide();
+                }
+                // choice === undefined (Escape/Cancel) or "Later": leave the status
+                // bar in place and re-prompt on a future activation.
+            } catch {
+                // Non-fatal.
+            }
+        };
+
+        context.subscriptions.push(
+            vscode.commands.registerCommand(MIGRATE_COMMAND, () => migrate(false))
+        );
+
+        // Show the unmissable modal exactly once; the status bar covers later sessions.
+        if (!context.globalState.get<boolean>(MODAL_SHOWN_KEY)) {
+            void context.globalState.update(MODAL_SHOWN_KEY, true);
+            void migrate(true);
+        }
+    } catch {
+        // Non-fatal — never block activation on the migration notice.
+    }
+}
diff --git a/src/extension.ts b/src/extension.ts
index 6644c1b..a02316c 100644
--- a/src/extension.ts
+++ b/src/extension.ts
@@ -12,6 +12,7 @@ import {
 } from './buildCheck';
 import * as telemetry from './telemetry';
 import { registerBinlogLanguageModelTools } from './languageModelTools';
+import { registerDeprecationNotice } from './deprecationNotice';
 import { projectSourcesAccessible, formatOverviewText } from './parsers';
 import * as path from 'path';
 import * as fs from 'fs';
@@ -172,6 +173,11 @@ export async function activate(context: vscode.ExtensionContext) {
     telemetry.trackActivation();
     setCiContext(context);
 
+    // This extension is deprecated in favor of the official ms-dotnettools
+    // extension. Register a persistent migration nudge (best-effort, never
+    // blocks activation): an unmissable modal once + a persistent status bar.
+    registerDeprecationNotice(context);
+
     // Expose binlog analysis as VS Code language-model tools so any agent
     // (@workspace, custom modes, agent mode) can use them — not just @binlog.
     registerBinlogLanguageModelTools(context, {