diff --git a/frontend/src/__tests__/plans.test.ts b/frontend/src/__tests__/plans.test.ts
index 188017121..18a015961 100644
--- a/frontend/src/__tests__/plans.test.ts
+++ b/frontend/src/__tests__/plans.test.ts
@@ -1441,16 +1441,51 @@ describe('Plans Module', () => {
         expect(chips?.textContent).not.toContain('Prod AWS');
       });
 
-      test('does not prefill when snapshot has more than one commitment', () => {
-        const second: api.Recommendation = { ...fixture, id: 'rec-771', service: 'rds' };
-        openCreatePlanModal([fixture, second]);
-
-        // populateTermSelect is called by setupRampScheduleHandlers / updateCommitmentOptions
-        // but NOT by prefillPurchaseConfigFromCommitment (which only runs for length===1)
-        // The provider/service select should NOT be forced to either rec's values
-        // We assert that the service select was not forced to 'ec2' alone
-        // (a multi-commitment plan requires manual selection)
-        expect(api.getAccount).not.toHaveBeenCalled();
+      // #898: extend prefill to a homogeneous multi-commitment selection. The
+      // "Plan from N selected" button only enables when provider/service/term/
+      // payment match across the selection, so the first commitment is a valid
+      // representative for the Purchase Configuration fields.
+      describe('prefill from multiple homogeneous commitments (#898)', () => {
+        test('prefills provider/service/term/payment from the shared values', () => {
+          const second: api.Recommendation = { ...fixture, id: 'rec-771', region: 'us-west-2' };
+          openCreatePlanModal([fixture, second]);
+
+          expect((document.getElementById('plan-provider') as HTMLSelectElement).value).toBe('aws');
+          expect((document.getElementById('plan-service') as HTMLSelectElement).value).toBe('ec2');
+          expect((document.getElementById('plan-term') as HTMLSelectElement).value).toBe('1');
+          expect((document.getElementById('plan-payment') as HTMLSelectElement).value).toBe('partial-upfront');
+        });
+
+        test('prefills the account chip when all commitments share one account', async () => {
+          (api.getAccount as jest.Mock).mockResolvedValueOnce({
+            id: 'acct-uuid-123',
+            name: 'Prod AWS',
+            external_id: '123456789012',
+          });
+          const second: api.Recommendation = { ...fixture, id: 'rec-771', region: 'us-west-2' };
+          openCreatePlanModal([fixture, second]);
+
+          await Promise.resolve();
+          await Promise.resolve();
+
+          expect(api.getAccount).toHaveBeenCalledWith('acct-uuid-123');
+          const hiddenIds = (document.getElementById('plan-account-ids') as HTMLInputElement).value;
+          expect(hiddenIds).toContain('acct-uuid-123');
+        });
+
+        test('leaves the account chip empty when commitments span accounts', async () => {
+          const second: api.Recommendation = { ...fixture, id: 'rec-771', cloud_account_id: 'acct-uuid-999' };
+          openCreatePlanModal([fixture, second]);
+
+          await Promise.resolve();
+
+          // Config still prefills from the homogeneous fields, but the account
+          // is ambiguous so no chip is fetched.
+          expect((document.getElementById('plan-service') as HTMLSelectElement).value).toBe('ec2');
+          expect(api.getAccount).not.toHaveBeenCalled();
+          const hiddenIds = (document.getElementById('plan-account-ids') as HTMLInputElement).value;
+          expect(hiddenIds).toBe('');
+        });
       });
     });
   });
diff --git a/frontend/src/plans.ts b/frontend/src/plans.ts
index 45d11f855..8d343d78a 100644
--- a/frontend/src/plans.ts
+++ b/frontend/src/plans.ts
@@ -836,8 +836,15 @@ async function setupPlanAccountsSection(planId?: string): Promise<void> {
 
 /**
  * Prefill the Purchase Configuration section (provider / service / term /
- * payment) from a single selected commitment. Called after form.reset() so
- * the defaults are already in place; each field is still editable. (#770)
+ * payment) from a representative selected commitment. Called after
+ * form.reset() so the defaults are already in place; each field is still
+ * editable. (#770)
+ *
+ * For a multi-commitment selection the caller passes the first commitment as
+ * the representative: the "Plan from N selected" button is only enabled when
+ * the selection is homogeneous (same provider/service/term/payment — see
+ * isHomogeneousSelection in recommendations.ts), so any element shares those
+ * four values. (#898)
  */
 function prefillPurchaseConfigFromCommitment(rec: api.Recommendation): void {
   const providerSelect = document.getElementById('plan-provider') as HTMLSelectElement | null;
@@ -921,10 +928,13 @@ export function openCreatePlanModal(snapshot?: readonly api.Recommendation[]): v
   (document.getElementById('plan-id') as HTMLInputElement).value = '';
   (document.getElementById('plan-form') as HTMLFormElement | null)?.reset();
 
-  // When exactly one commitment is selected, prefill the Purchase
-  // Configuration fields so the user does not have to re-enter them.
-  // Fields are still fully editable after prefill. (#770)
-  if (pendingPlanRecommendations.length === 1) {
+  // When one or more commitments are selected, prefill the Purchase
+  // Configuration fields so the user does not have to re-enter them. The
+  // first commitment is the representative: for a multi-selection the
+  // "Plan from N selected" button only enables on a homogeneous selection,
+  // so every element shares provider/service/term/payment. Fields are still
+  // fully editable after prefill. (#770, #898)
+  if (pendingPlanRecommendations.length >= 1) {
     prefillPurchaseConfigFromCommitment(pendingPlanRecommendations[0]!);
   }
 
@@ -943,13 +953,21 @@ export function openCreatePlanModal(snapshot?: readonly api.Recommendation[]): v
   planModalSession += 1;
 
   // setupPlanAccountsSection clears planSelectedAccounts and re-renders.
-  // When a single commitment carries a cloud_account_id, we look up that
-  // account after the section has reset and add it as a pre-selected chip.
+  // When every selected commitment carries the SAME cloud_account_id, we look
+  // up that account after the section has reset and add it as a pre-selected
+  // chip. Homogeneity of provider/service/term/payment (enforced by the
+  // "Plan from N selected" gate) does not imply a single account, so a
+  // multi-account selection leaves the chip empty for the user to fill. (#898)
   void setupPlanAccountsSection();
-  if (pendingPlanRecommendations.length === 1) {
-    const accountId = pendingPlanRecommendations[0]!.cloud_account_id;
-    if (accountId) {
-      void prefillAccountChipFromId(accountId, planModalSession);
+  if (pendingPlanRecommendations.length >= 1) {
+    const firstAccountId = pendingPlanRecommendations[0]!.cloud_account_id;
+    const sharedAccountId =
+      firstAccountId &&
+      pendingPlanRecommendations.every((r) => r.cloud_account_id === firstAccountId)
+        ? firstAccountId
+        : undefined;
+    if (sharedAccountId) {
+      void prefillAccountChipFromId(sharedAccountId, planModalSession);
     }
   }