diff --git a/static/js/utils/form.js b/static/js/utils/form.js
index 1f2c87c6c..b2a449e2a 100644
--- a/static/js/utils/form.js
+++ b/static/js/utils/form.js
@@ -3,10 +3,6 @@
 
   var formUtilities = [];
 
-  var FORM_GROUP_SELECTOR = '.form-group';
-  var FORM_GROUP_WITH_ERRORS_CLASS = 'form-group--has-error';
-
-
   /**
    *
    * Reactive Submit Button Utility
@@ -153,11 +149,13 @@
   var INTERACTIVE_FIELDSET_UTIL_TARGET_SELECTOR = '.interactive-fieldset--target';
 
   var INTERACTIVE_FIELDSET_INITIALIZED_CLASS = 'interactive-fieldset--initialized';
+  var INTERACTIVE_FIELDSET_CHILD_SELECTOR = 'input:not([disabled])';
 
   var interactiveFieldsetUtil = function(element) {
     var conditionalInput;
     var conditionalValue;
     var target;
+    var childInputs;
 
     function init() {
       if (!element) {
@@ -194,6 +192,8 @@
         throw new Error('Interactive Fieldset needs to be a target or have a target-ancestor!');
       }
 
+      childInputs = Array.from(element.querySelectorAll(INTERACTIVE_FIELDSET_CHILD_SELECTOR));
+
       // add event listener
       conditionalInput.addEventListener('input', updateVisibility);
 
@@ -211,7 +211,13 @@
     }
 
     function updateVisibility() {
-      target.classList.toggle('hidden', !matchesConditionalValue());
+      var active = matchesConditionalValue();
+      
+      target.classList.toggle('hidden', !active);
+
+      childInputs.forEach(function(el) {
+        el.toggleAttribute('disabled', !active);
+      });
     }
 
     function matchesConditionalValue() {
@@ -292,6 +298,10 @@
   var FORM_ERROR_REMOVER_INITIALIZED_CLASS = 'form-error-remover--initialized';
   var FORM_ERROR_REMOVER_INPUTS_SELECTOR = 'input:not([type="hidden"]), textarea, select';
 
+  var FORM_GROUP_SELECTOR = '.form-group';
+  var FORM_GROUP_WITH_ERRORS_CLASS = 'form-group--has-error';
+
+
   var formErrorRemoverUtil = function(element) {
     var formGroups;