diff --git a/src/core/catalog.js b/src/core/catalog.js
index 5b5b319c7..3f73e6d91 100644
--- a/src/core/catalog.js
+++ b/src/core/catalog.js
@@ -267,6 +267,10 @@ class Catalog {
     return markInfo;
   }
 
+  get hasStructTree() {
+    return this.#catDict.has("StructTreeRoot");
+  }
+
   get structTreeRoot() {
     let structTree = null;
     try {
diff --git a/src/core/worker.js b/src/core/worker.js
index 8ef7b10f4..1b6accb85 100644
--- a/src/core/worker.js
+++ b/src/core/worker.js
@@ -515,6 +515,7 @@ class WorkerMessageHandler {
       return Promise.all([
         pdfManager.ensureDoc("documentInfo"),
         pdfManager.ensureCatalog("metadata"),
+        pdfManager.ensureCatalog("hasStructTree"),
       ]);
     });
 
diff --git a/src/display/api.js b/src/display/api.js
index b279df994..75ed964d3 100644
--- a/src/display/api.js
+++ b/src/display/api.js
@@ -3077,6 +3077,7 @@ class WorkerTransport {
         metadata: results[1] ? new Metadata(results[1]) : null,
         contentDispositionFilename: this._fullReader?.filename ?? null,
         contentLength: this._fullReader?.contentLength ?? null,
+        hasStructTree: results[2],
       }));
     this.#methodPromises.set(name, promise);
     return promise;
diff --git a/web/app.js b/web/app.js
index a9a6e8d88..3d6b122f0 100644
--- a/web/app.js
+++ b/web/app.js
@@ -1719,12 +1719,21 @@ const PDFViewerApplication = {
    * @private
    */
   async _initializeMetadata(pdfDocument) {
-    const { info, metadata, contentDispositionFilename, contentLength } =
-      await pdfDocument.getMetadata();
+    const {
+      info,
+      metadata,
+      contentDispositionFilename,
+      contentLength,
+      hasStructTree,
+    } = await pdfDocument.getMetadata();
 
     if (pdfDocument !== this.pdfDocument) {
       return; // The document was closed while the metadata resolved.
     }
+    this.externalServices.reportTelemetry({
+      type: "taggedPDF",
+      data: hasStructTree,
+    });
     this.documentInfo = info;
     this.metadata = metadata;
     this._contentDispositionFilename ??= contentDispositionFilename;