diff --git a/source/change-streams/change-streams.md b/source/change-streams/change-streams.md
index 6021d97ec3..d862e9bf2a 100644
--- a/source/change-streams/change-streams.md
+++ b/source/change-streams/change-streams.md
@@ -227,6 +227,12 @@ class ChangeStreamDocument {
    */
   clusterTime: Timestamp;
 
+  /**
+   * When this operation was committed.
+   * Only present for events in a transaction and only when the `showExpandedEvents` change stream option is enabled.
+   */
+  commitTimestamp: Optional<Timestamp>;
+
 }
 
 class UpdateDescription {
@@ -1026,6 +1032,8 @@ There should be no backwards compatibility concerns.
 
 ## Changelog
 
+- 2026-01-30: Add `commitTimestamp` to `ChangeStreamDocument`.
+
 - 2025-09-08: Clarify resume behavior.
 
 - 2025-03-31: Update for expanded field visibility in server 8.2+
diff --git a/source/change-streams/tests/unified/change-streams-commitTimestamp.json b/source/change-streams/tests/unified/change-streams-commitTimestamp.json
new file mode 100644
index 0000000000..353aadc3f0
--- /dev/null
+++ b/source/change-streams/tests/unified/change-streams-commitTimestamp.json
@@ -0,0 +1,119 @@
+{
+  "description": "change-streams-commitTimestamp",
+  "schemaVersion": "1.7",
+  "runOnRequirements": [
+    {
+      "minServerVersion": "8.2.0",
+      "topologies": [
+        "replicaset",
+        "sharded"
+      ],
+      "serverless": "forbid"
+    }
+  ],
+  "createEntities": [
+    {
+      "client": {
+        "id": "client0"
+      }
+    },
+    {
+      "database": {
+        "id": "database0",
+        "client": "client0",
+        "databaseName": "database0"
+      }
+    },
+    {
+      "collection": {
+        "id": "collection0",
+        "database": "database0",
+        "collectionName": "collection0"
+      }
+    },
+    {
+      "session": {
+        "id": "session0",
+        "client": "client0"
+      }
+    }
+  ],
+  "initialData": [
+    {
+      "collectionName": "collection0",
+      "databaseName": "database0",
+      "documents": []
+    }
+  ],
+  "tests": [
+    {
+      "description": "when showExpandedEvents is true, commitTimestamp is included for operations in a transaction",
+      "operations": [
+        {
+          "name": "createChangeStream",
+          "object": "collection0",
+          "arguments": {
+            "pipeline": [],
+            "showExpandedEvents": true
+          },
+          "saveResultAsEntity": "changeStream0"
+        },
+        {
+          "name": "startTransaction",
+          "object": "session0"
+        },
+        {
+          "name": "insertOne",
+          "object": "collection0",
+          "arguments": {
+            "document": {
+              "x": 1
+            },
+            "session": "session0"
+          }
+        },
+        {
+          "name": "commitTransaction",
+          "object": "session0"
+        },
+        {
+          "name": "iterateUntilDocumentOrError",
+          "object": "changeStream0",
+          "expectResult": {
+            "operationType": "insert",
+            "ns": {
+              "db": "database0",
+              "coll": "collection0"
+            },
+            "commitTimestamp": {
+              "$$exists": true
+            }
+          }
+        },
+        {
+          "name": "insertOne",
+          "object": "collection0",
+          "arguments": {
+            "document": {
+              "x": 1
+            }
+          }
+        },
+        {
+          "name": "iterateUntilDocumentOrError",
+          "object": "changeStream0",
+          "expectResult": {
+            "operationType": "insert",
+            "ns": {
+              "db": "database0",
+              "coll": "collection0"
+            },
+            "commitTimestamp": {
+              "$$exists": false
+            }
+          }
+        }
+      ]
+    }
+  ]
+}
diff --git a/source/change-streams/tests/unified/change-streams-commitTimestamp.yml b/source/change-streams/tests/unified/change-streams-commitTimestamp.yml
new file mode 100644
index 0000000000..f525df519c
--- /dev/null
+++ b/source/change-streams/tests/unified/change-streams-commitTimestamp.yml
@@ -0,0 +1,65 @@
+description: "change-streams-commitTimestamp"
+schemaVersion: "1.7"
+runOnRequirements:
+  - minServerVersion: "8.2.0"
+    topologies: [ replicaset, sharded ]
+    serverless: forbid
+
+createEntities:
+  - client:
+      id: &client0 client0
+  - database:
+      id: &database0 database0
+      client: *client0
+      databaseName: *database0
+  - collection:
+      id: &collection0 collection0
+      database: *database0
+      collectionName: *collection0
+  - session:
+      id: &session0 session0
+      client: *client0
+
+initialData:
+  - collectionName: *collection0
+    databaseName: *database0
+    documents: []
+
+tests:
+  - description: "when showExpandedEvents is true, commitTimestamp is included for operations in a transaction"
+    operations:
+      - name: createChangeStream
+        object: *collection0
+        arguments:
+          pipeline: []
+          showExpandedEvents: true
+        saveResultAsEntity: &changeStream0 changeStream0
+      - name: startTransaction
+        object: *session0
+      - name: insertOne
+        object: *collection0
+        arguments:
+          document: { x: 1 }
+          session: *session0
+      - name: commitTransaction
+        object: *session0
+      - name: iterateUntilDocumentOrError
+        object: *changeStream0
+        expectResult:
+          operationType: insert
+          ns:
+            db: *database0
+            coll: *collection0
+          commitTimestamp: { $$exists: true }
+      - name: insertOne
+        object: *collection0
+        arguments:
+          document: { x: 1 }
+      - name: iterateUntilDocumentOrError
+        object: *changeStream0
+        expectResult:
+          operationType: insert
+          ns:
+            db: *database0
+            coll: *collection0
+          commitTimestamp: { $$exists: false }
\ No newline at end of file