diff --git a/schemas/compat-data-schema.md b/schemas/compat-data-schema.md
index f4f99287cf111a..e63d23060e35a9 100644
--- a/schemas/compat-data-schema.md
+++ b/schemas/compat-data-schema.md
@@ -369,6 +369,18 @@ Example for two flags required:
 }
 ```
 
+#### `implementation_url`
+
+An optional changeset URL or commit URL for the change which implemented the feature in the
+source code for the associated browser; e.g. a https://trac.webkit.org/changeset/ URL for a
+changeset whose subject line is in the form _"Enable [feature name/description]."_ or
+_"Enable [feature name/description] by default."_. The presence of an `implementation_url`
+value indicates that the associated browser has spec-conformant support for the feature in
+its source code. Therefore, an `implementation_url` value can be added even if the feature
+hasn't yet shipped in a stable release, but instead only in a Nightly, Canary, or Technology
+Preview release — or even if the feature hasn't yet shipped in any release at all, but has
+only landed in the source code for the associated browser.
+
 #### `partial_implementation`
 
 A `boolean` value indicating whether or not the implementation of the sub-feature
diff --git a/schemas/compat-data.schema.json b/schemas/compat-data.schema.json
index 033ec7d4dd71c7..9257ae044ca866 100644
--- a/schemas/compat-data.schema.json
+++ b/schemas/compat-data.schema.json
@@ -39,6 +39,12 @@
             "required": ["type", "name"]
           }
         },
+        "implementation_url": {
+          "type": "string",
+          "format": "uri",
+          "pattern": "^http(s)?:\/\/[^#]+#.+",
+          "description": "An optional changeset URL or commit URL for the change which implemented the feature in the source code for the associated browser."
+        },
         "partial_implementation": {
           "type": "boolean",
           "description": "A boolean value indicating whether or not the implementation of the sub-feature deviates from the specification in a way that may cause compatibility problems. It defaults to false (no interoperability problems expected). If set to true, it is recommended that you add a note explaining how it diverges from the standard (such as that it implements an old version of the standard, for example)."
diff --git a/types.d.ts b/types.d.ts
index e5a8579bbba725..076569e5c0397d 100644
--- a/types.d.ts
+++ b/types.d.ts
@@ -195,6 +195,13 @@ export interface SimpleSupportStatement {
      */
     value_to_set?: string;
   }[];
+
+  /**
+   * An optional changeset URL or commit URL for the change which implemented the feature in the
+   * source code for the associated browser; e.g. a https://trac.webkit.org/changeset/ URL.
+   */
+  implementation_url?: string;
+
   /**
    * A `boolean` value indicating whether or not the implementation of the sub-feature follows
    * the current specification closely enough to not create major interoperability problems.