diff --git a/app/javascript/packs/admin/editUser.jsx b/app/javascript/packs/admin/editUser.jsx
index c71b37e87..235388220 100644
--- a/app/javascript/packs/admin/editUser.jsx
+++ b/app/javascript/packs/admin/editUser.jsx
@@ -1,8 +1,42 @@
 import { initializeDropdown } from '@utilities/dropdownUtils';
 
-let preact;
-let AdminModal;
-const modalContents = new Map();
+function adjustCreditRange(event) {
+  const {
+    target: { value, name, form },
+  } = event;
+
+  if (name === 'user[credit_action]') {
+    const creditAmount = form['user[credit_amount]'];
+
+    if (value === 'Add') {
+      if (creditAmount.getAttribute('data-old-max')) {
+        creditAmount.setAttribute(
+          'max',
+          creditAmount.getAttribute('data-old-max'),
+        );
+      }
+    } else {
+      creditAmount.setAttribute(
+        'data-old-max',
+        creditAmount.getAttribute('max'),
+      );
+      creditAmount.setAttribute('max', creditAmount.dataset.unspentCredits);
+    }
+  }
+}
+
+function enableEvents(key, enabled = true) {
+  if (!eventMap.has(key)) {
+    return;
+  }
+
+  const [eventType, handler] = eventMap.get(key);
+
+  modalContainer[enabled ? 'addEventListener' : 'removeEventListener'](
+    eventType,
+    handler,
+  );
+}
 
 function getModalContents(modalContentSelector) {
   if (!modalContents.has(modalContentSelector)) {
@@ -17,6 +51,16 @@ function getModalContents(modalContentSelector) {
   return modalContents.get(modalContentSelector);
 }
 
+let preact;
+let AdminModal;
+const modalContents = new Map();
+
+// Keys are the modalContentSelector data attribute on a button that opens a modal.
+// Values are a tuple containing the event type and handler to add to the modal container.
+const eventMap = new Map();
+
+eventMap.set('#adjust-balance', ['change', adjustCreditRange]);
+
 // Append an empty div to the end of the document so that is does not affect the layout.
 const modalContainer = document.createElement('div');
 document.body.appendChild(modalContainer);
@@ -48,12 +92,15 @@ const openModal = async (event) => {
 
   const { modalTitle, modalSize, modalContentSelector } = dataset;
 
+  enableEvents(modalContentSelector);
+
   render(
     <AdminModal
       title={modalTitle}
       size={modalSize}
       onClose={() => {
         render(null, modalContainer);
+        enableEvents(modalContentSelector, false);
       }}
     >
       <div
diff --git a/app/views/admin/users/widgets/_credits.html.erb b/app/views/admin/users/widgets/_credits.html.erb
index 7e6b5bf70..f56444cb9 100644
--- a/app/views/admin/users/widgets/_credits.html.erb
+++ b/app/views/admin/users/widgets/_credits.html.erb
@@ -29,7 +29,10 @@
                          value: 1,
                          size: 5,
                          min: 1,
-                         max: 9999 %>
+                         max: 9999,
+                         data: {
+                           "unspent-credits": @user.unspent_credits_count
+                         } %>
       <%= f.label :credit_amount, "credits", class: "color-secondary flex-1", "aria-label": "Amount of credits to add or remove" %>
       </div>
     </div>
diff --git a/cypress/integration/seededFlows/adminFlows/users/manageCredits.spec.js b/cypress/integration/seededFlows/adminFlows/users/manageCredits.spec.js
index 546cc74d8..db848e59e 100644
--- a/cypress/integration/seededFlows/adminFlows/users/manageCredits.spec.js
+++ b/cypress/integration/seededFlows/adminFlows/users/manageCredits.spec.js
@@ -68,16 +68,38 @@ describe('Manage User Credits', () => {
         cy.findByRole('combobox', { name: 'Adjust balance' }).select('Remove');
         cy.findByRole('spinbutton', {
           name: 'Amount of credits to add or remove',
-        }).type('10');
+        })
+          .as('credits')
+          .type('10');
         cy.findByRole('textbox', {
           name: 'Why are you adjusting credits?',
         }).type('some reason');
         cy.findByRole('button', { name: 'Adjust' }).click();
       });
 
-      cy.getModal().should('not.exist');
-      closeUserUpdatedMessage('Credits have been removed.');
-      cy.findByTestId('user-credits').should('have.text', '0');
+      cy.getModal().should('exist');
+      cy.findByTestId('user-credits').should('have.text', '100');
+    });
+
+    it('should have correct max credits for adding and removing credits', () => {
+      cy.findByTestId('user-credits').should('have.text', '100');
+
+      openCreditsModal().within(() => {
+        cy.findByRole('combobox', { name: 'Adjust balance' })
+          .as('adjustBalance')
+          .select('Add');
+        cy.findByRole('spinbutton', {
+          name: 'Amount of credits to add or remove',
+        })
+          .as('creditAmount')
+          .should('have.attr', 'max', '9999');
+
+        cy.get('@adjustBalance').select('Remove');
+        cy.get('@creditAmount').should('have.attr', 'max', '100');
+
+        cy.get('@adjustBalance').select('Add');
+        cy.get('@creditAmount').should('have.attr', 'max', '9999');
+      });
     });
   });
 });