diff --git a/js/phetioAPIValidation.ts b/js/phetioAPIValidation.ts
index 4a7d0990..20521f1a 100644
--- a/js/phetioAPIValidation.ts
+++ b/js/phetioAPIValidation.ts
@@ -34,7 +34,7 @@
 import Tandem, { DYNAMIC_ARCHETYPE_NAME } from './Tandem.js';
 import tandemNamespace from './tandemNamespace.js';
 import IOType from './types/IOType.js';
-import PhetioObject from './PhetioObject.js';
+import PhetioObject, { LinkedElement } from './PhetioObject.js';
 import { PhetioObjectMetadata } from './TandemConstants.js';
 
 // constants
@@ -83,6 +83,7 @@ class PhetioAPIValidation {
   public onSimStarted(): void {
     if ( this.enabled && phet.joist.sim.allScreensCreated ) {
       this.validateOverridesFile();
+      this.validatePreferencesModel();
     }
 
     if ( phet.preloads.phetio.queryParameters.phetioPrintAPIProblems && this.apiMismatches ) {
@@ -93,6 +94,24 @@ class PhetioAPIValidation {
     this.simHasStarted = true;
   }
 
+  /**
+   * All core elements in the preferencesModel should be phetioReadOnly: false so they can be set over the API
+   * or from within studio, but phetioState: false so they are not captured with save states.
+   */
+  public validatePreferencesModel(): void {
+    Object.keys( phet.phetio.phetioEngine.phetioObjectMap ).filter( key => key.includes( '.preferencesModel.' ) )
+      .forEach( preferencesKey => {
+
+        let phetioObject = phet.phetio.phetioEngine.phetioObjectMap[ preferencesKey ];
+
+        while ( phetioObject instanceof LinkedElement ) {
+          phetioObject = phetioObject.element;
+        }
+        assert && assert( !phetioObject.phetioReadOnly, 'preferences model and its descendants should be phetioReadOnly: false, key=' + preferencesKey );
+        // assert && assert( !phetioObject.phetioState, 'preferences model and its descendants should be phetioState: false, key=' + preferencesKey );
+      } );
+  }
+
   /**
    * Checks if a removed phetioObject is part of a Group
    */