diff --git a/CRM/Grant/BAO/GrantBudget.php b/CRM/Grant/BAO/GrantBudget.php
index b100633..13a6151 100644
--- a/CRM/Grant/BAO/GrantBudget.php
+++ b/CRM/Grant/BAO/GrantBudget.php
@@ -13,7 +13,7 @@ class CRM_Grant_BAO_GrantBudget extends CRM_Grant_DAO_GrantBudget {
   }
 
   /**
-   * Build Fiscal year option list.
+   * Get grant budget for fiscal year and financial type.
    *
    * @param $params array
    *
@@ -78,4 +78,40 @@ class CRM_Grant_BAO_GrantBudget extends CRM_Grant_DAO_GrantBudget {
     return $grantBudget;
   }
 
+  /**
+   * Validate grant.
+   *
+   * @param $params array
+   *
+   * @return bool
+   */
+  public static function checkBudget($params, $grantId) {
+    $year = date('Y', strtotime($params['decision_date']));
+    $grantBudget = civicrm_api3('GrantBudget', 'getbudget', [
+      'financial_type_id' => $params['financial_type_id'],
+      'fiscal_year' => $year,
+    ]);
+    $grantBudget = reset($grantBudget['values']);
+    $isError = FALSE;
+    if ($grantBudget) {
+      $balanceAmount = CRM_Utils_Rule::cleanMoney($grantBudget['balance_amount']);
+      $amountGranted = CRM_Utils_Rule::cleanMoney($params['amount_granted']);
+      if ($grantId) {
+        $oldGrantValues = civicrm_api3('Grant', 'getsingle', [
+          'return' => ["amount_granted", 'financial_type_id', 'decision_date'],
+          'id' => $grantId,
+        ]);
+        if ($oldGrantValues['financial_type_id'] == $params['financial_type_id']
+          && $year == date('Y', strtotime($oldGrantValues['decision_date']))
+        ) {
+          $amountGranted -= $oldGrantValues['amount_granted'];
+        }
+      }
+      if ($balanceAmount < $amountGranted) {
+        $isError = TRUE;
+      }
+    }
+    return [$isError, $grantBudget];
+  }
+
 }
diff --git a/annualgrantbudgets.php b/annualgrantbudgets.php
index d543b77..6be5457 100644
--- a/annualgrantbudgets.php
+++ b/annualgrantbudgets.php
@@ -237,18 +237,9 @@ function annualgrantbudgets_civicrm_validateForm($formName, &$fields, &$files, &
     if ($paidStatusID != $fields['status_id']) {
       return;
     }
-    $year = date('Y', strtotime($fields['decision_date']));
-    $grantBudget = civicrm_api3('GrantBudget', 'getbudget', [
-      'financial_type_id' => $fields['financial_type_id'],
-      'fiscal_year' => $year,
-    ]);
-    $grantBudget = reset($grantBudget['values']);
-    if ($grantBudget && !empty($grantBudget['id'])) {
-      $balanceAmount = CRM_Utils_Rule::cleanMoney($grantBudget['balance_amount']);
-      $amountGranted = CRM_Utils_Rule::cleanMoney($fields['amount_granted']);
-      if ($balanceAmount < $amountGranted) {
-        $errors['amount_granted'] = ts("The annual budget for this grant is {$grantBudget['budget']}. Grants totaling {$grantBudget['total_amount_granted']} have been made. {$grantBudget['balance_amount']} remains.");
-      }
+    list($isError, $grantBudget) = CRM_Grant_BAO_GrantBudget::checkBudget($fields, $form->getVar('_id'));
+    if ($isError) {
+      $errors['amount_granted'] = ts("The annual budget for this grant is {$grantBudget['budget']}. Grants totaling {$grantBudget['total_amount_granted']} have been made. {$grantBudget['balance_amount']} remains.");
     }
   }
 }
diff --git a/api/v3/GrantBudget.php b/api/v3/GrantBudget.php
index d65cea6..e745658 100644
--- a/api/v3/GrantBudget.php
+++ b/api/v3/GrantBudget.php
@@ -69,8 +69,5 @@ function _civicrm_api3_grant_budget_getbudget_spec(&$spec) {
     'api.required' => 1,
     'title' => ts('Fiscal Year'),
     'type' => CRM_Utils_Type::T_INT,
-    'pseudoconstant' => [
-      'callback' => 'CRM_Grant_BAO_GrantBudget::getFiscalyear',
-    ],
   ];
 }