diff --git a/.changeset/hip-actors-hide.md b/.changeset/hip-actors-hide.md
new file mode 100644
index 000000000..487ce1dc8
--- /dev/null
+++ b/.changeset/hip-actors-hide.md
@@ -0,0 +1,5 @@
+---
+"ember-resources": patch
+---
+
+when using RemoteData, isError should be true when the http status code is >= 400. Resolves #825"
diff --git a/ember-resources/src/util/remote-data.ts b/ember-resources/src/util/remote-data.ts
index ddb1dd387..ffe033892 100644
--- a/ember-resources/src/util/remote-data.ts
+++ b/ember-resources/src/util/remote-data.ts
@@ -67,9 +67,13 @@ export class State<T = unknown> {
 
   /**
    * true if the request throws an exception
+   * or if the request.status is >= 400
    */
   get isError() {
-    return this.isRejected;
+    let httpError = this.status && this.status >= 400;
+    let promiseThrew = this.isRejected;
+
+    return httpError || promiseThrew;
   }
 }