diff --git a/packages/mongodb-constants/src/filter.spec.ts b/packages/mongodb-constants/src/filter.spec.ts
index 008c5045b..f1f169d74 100644
--- a/packages/mongodb-constants/src/filter.spec.ts
+++ b/packages/mongodb-constants/src/filter.spec.ts
@@ -208,26 +208,5 @@ describe('completer', function () {
         }
       });
     });
-
-    it('should include $$IDX system variable gated to MongoDB 8.3+', function () {
-      const idx = ALL_CONSTANTS.find((c) => c.value === '$$IDX');
-      expect(idx).to.exist;
-      expect(idx?.version).to.eq('8.3.0');
-      expect(idx?.meta).to.eq('variable:system');
-    });
-
-    it('should return $$IDX for server 8.3+ but not for older servers', function () {
-      const withIdx = getFilteredCompletions(
-        { serverVersion: '8.3.0' },
-        ALL_CONSTANTS,
-      ).map((c) => c.value);
-      expect(withIdx).to.include('$$IDX');
-
-      const withoutIdx = getFilteredCompletions(
-        { serverVersion: '8.2.0' },
-        ALL_CONSTANTS,
-      ).map((c) => c.value);
-      expect(withoutIdx).to.not.include('$$IDX');
-    });
   });
 });
diff --git a/packages/mongodb-constants/src/system-variables.ts b/packages/mongodb-constants/src/system-variables.ts
index c055d6cf0..2fe23abf6 100644
--- a/packages/mongodb-constants/src/system-variables.ts
+++ b/packages/mongodb-constants/src/system-variables.ts
@@ -56,15 +56,6 @@ const SYSTEM_VARIABLES = [
     version: '3.0.0',
     description: 'One of the allowed results of a `$redact` expression.',
   },
-  {
-    name: '$$IDX',
-    value: '$$IDX',
-    score: 1,
-    meta: 'variable:system',
-    version: '8.3.0',
-    description:
-      'A variable that references the index of the current array element in $map, $filter, and $reduce expressions. Use arrayIndexAs to specify a custom name instead.',
-  },
   {
     name: '$$PRUNE',
     value: '$$PRUNE',
diff --git a/packages/mongodb-ts-autocomplete/src/autocompleter.spec.ts b/packages/mongodb-ts-autocomplete/src/autocompleter.spec.ts
index 2713f05fd..d869a96a6 100644
--- a/packages/mongodb-ts-autocomplete/src/autocompleter.spec.ts
+++ b/packages/mongodb-ts-autocomplete/src/autocompleter.spec.ts
@@ -321,19 +321,6 @@ service host, so typescript wouldn't load all the dependencies.
     }
   });
 
-  it('suggests arrayIndexAs inside $filter, $map, $reduce operators', async function () {
-    const operators = ['$filter', '$map', '$reduce'] as const;
-    for (const op of operators) {
-      const completions = await autocompleter.autocomplete(
-        `db.foo.aggregate([{ $project: { result: { ${op}: { array`,
-      );
-      const names = completions.map((c) => c.name);
-      expect(names, `${op} should suggest arrayIndexAs`).to.include(
-        'arrayIndexAs',
-      );
-    }
-  });
-
   describe('getConnectionSchemaCode', function () {
     it('generates code for a connection', async function () {
       const docs = [
diff --git a/packages/mql-typescript/out/schema.d.ts b/packages/mql-typescript/out/schema.d.ts
index 40f0aee74..9163ee0d2 100644
--- a/packages/mql-typescript/out/schema.d.ts
+++ b/packages/mql-typescript/out/schema.d.ts
@@ -1560,12 +1560,6 @@ export namespace Aggregation.Expression {
        */
       as?: string;
 
-      /**
-       * A name for the variable that represents the index of the array element. Available in MongoDB 8.3+.
-       * If not specified, the index is available as $$IDX.
-       */
-      arrayIndexAs?: string;
-
       /**
        * A number expression that restricts the number of matching array elements that $filter returns. You cannot specify a limit less than 1. The matching array elements are returned in the order they appear in the input array.
        * If the specified limit is greater than the number of matching array elements, $filter returns all matching array elements. If the limit is null, $filter returns all matching array elements.
@@ -2132,12 +2126,6 @@ export namespace Aggregation.Expression {
        */
       as?: ResolvesToString<S>;
 
-      /**
-       * A name for the variable that represents the index of the array element. Available in MongoDB 8.3+.
-       * If not specified, the index is available as $$IDX.
-       */
-      arrayIndexAs?: string;
-
       /**
        * An expression that is applied to each element of the input array. The expression references each element individually with the variable name specified in as.
        */
@@ -2539,22 +2527,6 @@ export namespace Aggregation.Expression {
        */
       initialValue: Expression<S>;
 
-      /**
-       * A name for the variable that represents each element of the input array. Defaults to $$this. Available in MongoDB 8.3+.
-       */
-      as?: string;
-
-      /**
-       * A name for the variable that represents the cumulative value. Defaults to $$value. Available in MongoDB 8.3+.
-       */
-      valueAs?: string;
-
-      /**
-       * A name for the variable that represents the index of the array element. Available in MongoDB 8.3+.
-       * If not specified, the index is available as $$IDX.
-       */
-      arrayIndexAs?: string;
-
       /**
        * A valid expression that $reduce applies to each element in the input array in left-to-right order. Wrap the input value with $reverseArray to yield the equivalent of applying the combining expression from right-to-left.
        * During evaluation of the in expression, two variables will be available: