diff --git a/src/services/__tests__/splitApi.spec.ts b/src/services/__tests__/splitApi.spec.ts
index 07d6dec4..d5550f93 100644
--- a/src/services/__tests__/splitApi.spec.ts
+++ b/src/services/__tests__/splitApi.spec.ts
@@ -60,7 +60,12 @@ describe('splitApi', () => {
     splitApi.postMetricsUsage('fake-body');
     assertHeaders(settings, fetchMock.mock.calls[8][1].headers);
 
-    expect(telemetryTrackerMock.trackHttp).toBeCalledTimes(9);
+    splitApi.fetchMyLargeSegments('userKey');
+    [url, { headers }] = fetchMock.mock.calls[9];
+    assertHeaders(settings, headers);
+    expect(url).toBe('sdk/myLargeSegments/userKey');
+
+    expect(telemetryTrackerMock.trackHttp).toBeCalledTimes(10);
 
     telemetryTrackerMock.trackHttp.mockClear();
     fetchMock.mockClear();
diff --git a/src/services/splitApi.ts b/src/services/splitApi.ts
index 9e2223ea..51f1a02a 100644
--- a/src/services/splitApi.ts
+++ b/src/services/splitApi.ts
@@ -4,7 +4,7 @@ import { splitHttpClientFactory } from './splitHttpClient';
 import { ISplitApi } from './types';
 import { objectAssign } from '../utils/lang/objectAssign';
 import { ITelemetryTracker } from '../trackers/types';
-import { SPLITS, IMPRESSIONS, IMPRESSIONS_COUNT, EVENTS, TELEMETRY, TOKEN, SEGMENT, MY_SEGMENT } from '../utils/constants';
+import { SPLITS, IMPRESSIONS, IMPRESSIONS_COUNT, EVENTS, TELEMETRY, TOKEN, SEGMENT, MY_SEGMENT, MY_LARGE_SEGMENT } from '../utils/constants';
 import { ERROR_TOO_MANY_SETS } from '../logger/constants';
 
 const noCacheHeaderOptions = { headers: { 'Cache-Control': 'no-cache' } };
@@ -78,6 +78,11 @@ export function splitApiFactory(
       return splitHttpClient(url, noCache ? noCacheHeaderOptions : undefined, telemetryTracker.trackHttp(MY_SEGMENT));
     },
 
+    fetchMyLargeSegments(userMatchingKey: string, noCache?: boolean) {
+      const url = `${urls.sdk}/myLargeSegments/${encodeURIComponent(userMatchingKey)}`;
+      return splitHttpClient(url, noCache ? noCacheHeaderOptions : undefined, telemetryTracker.trackHttp(MY_LARGE_SEGMENT));
+    },
+
     /**
      * Post events.
      *
diff --git a/src/services/types.ts b/src/services/types.ts
index 116ccec5..a5dfde2a 100644
--- a/src/services/types.ts
+++ b/src/services/types.ts
@@ -62,6 +62,7 @@ export interface ISplitApi {
 	fetchSplitChanges: IFetchSplitChanges
 	fetchSegmentChanges: IFetchSegmentChanges
 	fetchMySegments: IFetchMySegments
+	fetchMyLargeSegments: IFetchMySegments
 	postEventsBulk: IPostEventsBulk
 	postUniqueKeysBulkCs: IPostUniqueKeysBulkCs
 	postUniqueKeysBulkSs: IPostUniqueKeysBulkSs
diff --git a/src/sync/submitters/types.ts b/src/sync/submitters/types.ts
index 440f466a..210cf603 100644
--- a/src/sync/submitters/types.ts
+++ b/src/sync/submitters/types.ts
@@ -113,7 +113,8 @@ export type TELEMETRY = 'te';
 export type TOKEN = 'to';
 export type SEGMENT = 'se';
 export type MY_SEGMENT = 'ms';
-export type OperationType = SPLITS | IMPRESSIONS | IMPRESSIONS_COUNT | EVENTS | TELEMETRY | TOKEN | SEGMENT | MY_SEGMENT;
+export type MY_LARGE_SEGMENT = 'mls';
+export type OperationType = SPLITS | IMPRESSIONS | IMPRESSIONS_COUNT | EVENTS | TELEMETRY | TOKEN | SEGMENT | MY_SEGMENT | MY_LARGE_SEGMENT;
 
 export type LastSync = Partial<Record<OperationType, number | undefined>>
 export type HttpErrors = Partial<Record<OperationType, { [statusCode: string]: number }>>
diff --git a/src/utils/constants/index.ts b/src/utils/constants/index.ts
index 51decc18..41a14e0a 100644
--- a/src/utils/constants/index.ts
+++ b/src/utils/constants/index.ts
@@ -76,6 +76,7 @@ export const TELEMETRY = 'te';
 export const TOKEN = 'to';
 export const SEGMENT = 'se';
 export const MY_SEGMENT = 'ms';
+export const MY_LARGE_SEGMENT = 'mls';
 
 export const TREATMENT = 't';
 export const TREATMENTS = 'ts';