diff --git a/docs/usage/configuration-options.md b/docs/usage/configuration-options.md
index b21d513dc1b8a5eef8d2cc0244cd520d052d14d7..cf9b4062f3ac60b16cdc0d212828649f933e2a7f 100644
--- a/docs/usage/configuration-options.md
+++ b/docs/usage/configuration-options.md
@@ -631,6 +631,12 @@ Because `fileMatch` is mergeable, you don't need to duplicate the defaults and c
 If you configure `fileMatch` then it must be within a manager object (e.g. `dockerfile` in the above example).
 The full list of supported managers can be found [here](https://docs.renovatebot.com/modules/manager/).
 
+## filterUnavailableUsers
+
+When this option is enabled PRs are not assigned to users that are unavailable.
+This option only works on platforms that support the concept of user availability.
+For now, you can only use this option on the GitLab platform.
+
 ## followTag
 
 Caution: advanced functionality. Only use it if you're sure you know what you're doing.
diff --git a/lib/config/definitions.ts b/lib/config/definitions.ts
index 76dcf0d28c0de304cb6e9b6ddf26f33c9dc163a5..3c77b49792aaa2439ceb8dc5cf496161aca35200 100644
--- a/lib/config/definitions.ts
+++ b/lib/config/definitions.ts
@@ -1497,6 +1497,12 @@ const options: RenovateOptions[] = [
     type: 'boolean',
     default: false,
   },
+  {
+    name: 'filterUnavailableUsers',
+    description: 'Filter reviewers and assignees based on their availability.',
+    type: 'boolean',
+    default: false,
+  },
   {
     name: 'reviewersSampleSize',
     description: 'Take a random sample of given size from reviewers.',
diff --git a/lib/config/types.ts b/lib/config/types.ts
index 2ef022c21c49b8a90bec37c8efbf733ed04b8724..cbbbd973379c4e7797d31d800b0f202f185a9dbd 100644
--- a/lib/config/types.ts
+++ b/lib/config/types.ts
@@ -207,6 +207,7 @@ export interface AssigneesAndReviewersConfig {
   reviewers?: string[];
   reviewersSampleSize?: number;
   additionalReviewers?: string[];
+  filterUnavailableUsers?: boolean;
 }
 
 export type UpdateType =
diff --git a/lib/platform/gitlab/__snapshots__/index.spec.ts.snap b/lib/platform/gitlab/__snapshots__/index.spec.ts.snap
index e5778843549a5f994a0d3bc77098d7dc9c0907f6..f63b6d3f9fa792526192cb55f482e5c4e4c92810 100644
--- a/lib/platform/gitlab/__snapshots__/index.spec.ts.snap
+++ b/lib/platform/gitlab/__snapshots__/index.spec.ts.snap
@@ -798,6 +798,83 @@ Array [
 ]
 `;
 
+exports[`platform/gitlab/index filterUnavailableUsers(users) filters users that are busy 1`] = `
+Array [
+  "john",
+]
+`;
+
+exports[`platform/gitlab/index filterUnavailableUsers(users) filters users that are busy 2`] = `
+Array [
+  Object {
+    "headers": Object {
+      "accept": "application/json",
+      "accept-encoding": "gzip, deflate, br",
+      "authorization": "Bearer abc123",
+      "host": "gitlab.com",
+      "user-agent": "https://github.com/renovatebot/renovate",
+    },
+    "method": "GET",
+    "url": "https://gitlab.com/api/v4/users/maria/status",
+  },
+  Object {
+    "headers": Object {
+      "accept": "application/json",
+      "accept-encoding": "gzip, deflate, br",
+      "authorization": "Bearer abc123",
+      "host": "gitlab.com",
+      "user-agent": "https://github.com/renovatebot/renovate",
+    },
+    "method": "GET",
+    "url": "https://gitlab.com/api/v4/users/john/status",
+  },
+]
+`;
+
+exports[`platform/gitlab/index filterUnavailableUsers(users) keeps users with failing requests 1`] = `
+Array [
+  "maria",
+]
+`;
+
+exports[`platform/gitlab/index filterUnavailableUsers(users) keeps users with failing requests 2`] = `
+Array [
+  Object {
+    "headers": Object {
+      "accept": "application/json",
+      "accept-encoding": "gzip, deflate, br",
+      "authorization": "Bearer abc123",
+      "host": "gitlab.com",
+      "user-agent": "https://github.com/renovatebot/renovate",
+    },
+    "method": "GET",
+    "url": "https://gitlab.com/api/v4/users/maria/status",
+  },
+]
+`;
+
+exports[`platform/gitlab/index filterUnavailableUsers(users) keeps users with missing availability 1`] = `
+Array [
+  "maria",
+]
+`;
+
+exports[`platform/gitlab/index filterUnavailableUsers(users) keeps users with missing availability 2`] = `
+Array [
+  Object {
+    "headers": Object {
+      "accept": "application/json",
+      "accept-encoding": "gzip, deflate, br",
+      "authorization": "Bearer abc123",
+      "host": "gitlab.com",
+      "user-agent": "https://github.com/renovatebot/renovate",
+    },
+    "method": "GET",
+    "url": "https://gitlab.com/api/v4/users/maria/status",
+  },
+]
+`;
+
 exports[`platform/gitlab/index findIssue() finds issue 1`] = `
 Array [
   Object {
diff --git a/lib/platform/gitlab/http.ts b/lib/platform/gitlab/http.ts
index 51a836de629ab27f2f9b5526a2f9de4bd97fb50b..bab2b0f80378cd7b03489a9361b592a7be32cdd7 100644
--- a/lib/platform/gitlab/http.ts
+++ b/lib/platform/gitlab/http.ts
@@ -1,4 +1,6 @@
+import { logger } from '../../logger';
 import { GitlabHttp } from '../../util/http/gitlab';
+import type { GitlabUserStatus } from './types';
 
 export const gitlabApi = new GitlabHttp();
 
@@ -7,3 +9,14 @@ export async function getUserID(username: string): Promise<number> {
     await gitlabApi.getJson<{ id: number }[]>(`users?username=${username}`)
   ).body[0].id;
 }
+
+export async function isUserBusy(user: string): Promise<boolean> {
+  try {
+    const url = `/users/${user}/status`;
+    const userStatus = (await gitlabApi.getJson<GitlabUserStatus>(url)).body;
+    return userStatus.availability === 'busy';
+  } catch (err) {
+    logger.warn({ err }, 'Failed to get user status');
+    return false;
+  }
+}
diff --git a/lib/platform/gitlab/index.spec.ts b/lib/platform/gitlab/index.spec.ts
index b60e0ac2eed26be5bda59b665f36163320a45eb5..9f31a17ae240cb282b10359b979a987eb0e654ba 100644
--- a/lib/platform/gitlab/index.spec.ts
+++ b/lib/platform/gitlab/index.spec.ts
@@ -1614,4 +1614,44 @@ These updates have all been created already. Click a checkbox below to force a r
       expect(httpMock.getTrace()).toMatchSnapshot();
     });
   });
+  describe('filterUnavailableUsers(users)', () => {
+    it('filters users that are busy', async () => {
+      httpMock
+        .scope(gitlabApiHost)
+        .get('/api/v4/users/maria/status')
+        .reply(200, {
+          availability: 'busy',
+        })
+        .get('/api/v4/users/john/status')
+        .reply(200, {
+          availability: 'not_set',
+        });
+      const filteredUsers = await gitlab.filterUnavailableUsers([
+        'maria',
+        'john',
+      ]);
+      expect(filteredUsers).toMatchSnapshot();
+      expect(httpMock.getTrace()).toMatchSnapshot();
+    });
+
+    it('keeps users with missing availability', async () => {
+      httpMock
+        .scope(gitlabApiHost)
+        .get('/api/v4/users/maria/status')
+        .reply(200, {});
+      const filteredUsers = await gitlab.filterUnavailableUsers(['maria']);
+      expect(filteredUsers).toMatchSnapshot();
+      expect(httpMock.getTrace()).toMatchSnapshot();
+    });
+
+    it('keeps users with failing requests', async () => {
+      httpMock
+        .scope(gitlabApiHost)
+        .get('/api/v4/users/maria/status')
+        .reply(404);
+      const filteredUsers = await gitlab.filterUnavailableUsers(['maria']);
+      expect(filteredUsers).toMatchSnapshot();
+      expect(httpMock.getTrace()).toMatchSnapshot();
+    });
+  });
 });
diff --git a/lib/platform/gitlab/index.ts b/lib/platform/gitlab/index.ts
index 8ea18a0cd42b3bcb660ab2724113365e76891fdc..6faaf766cc14ce0ef00ea339cd9ea079c9d15b51 100755
--- a/lib/platform/gitlab/index.ts
+++ b/lib/platform/gitlab/index.ts
@@ -40,7 +40,7 @@ import type {
   UpdatePrConfig,
 } from '../types';
 import { smartTruncate } from '../utils/pr-body';
-import { getUserID, gitlabApi } from './http';
+import { getUserID, gitlabApi, isUserBusy } from './http';
 import { getMR, updateMR } from './merge-request';
 import type {
   GitLabMergeRequest,
@@ -1067,3 +1067,15 @@ export async function ensureCommentRemoval({
 export function getVulnerabilityAlerts(): Promise<VulnerabilityAlert[]> {
   return Promise.resolve([]);
 }
+
+export async function filterUnavailableUsers(
+  users: string[]
+): Promise<string[]> {
+  const filteredUsers = [];
+  for (const user of users) {
+    if (!(await isUserBusy(user))) {
+      filteredUsers.push(user);
+    }
+  }
+  return filteredUsers;
+}
diff --git a/lib/platform/gitlab/types.ts b/lib/platform/gitlab/types.ts
index 607b3e973ea0c1d93e48ae6571f666c6a6b73186..f35eba0b51b4c55aab63c6d88327fe25f33a44a6 100644
--- a/lib/platform/gitlab/types.ts
+++ b/lib/platform/gitlab/types.ts
@@ -51,3 +51,11 @@ export interface RepoResponse {
   merge_method: MergeMethod;
   path_with_namespace: string;
 }
+
+// See https://gitlab.com/gitlab-org/gitlab/-/blob/master/app/graphql/types/user_status_type.rb
+export interface GitlabUserStatus {
+  message?: string;
+  message_html?: string;
+  emoji?: string;
+  availability: 'not_set' | 'busy';
+}
diff --git a/lib/platform/types.ts b/lib/platform/types.ts
index 89345dc4518d357928432cb25ca49b80bc7a48aa..467dafdd67cf1a7ae4c889997be7515ff09c0e23 100644
--- a/lib/platform/types.ts
+++ b/lib/platform/types.ts
@@ -177,4 +177,5 @@ export interface Platform {
   ): Promise<BranchStatus>;
   getBranchPr(branchName: string): Promise<Pr | null>;
   initPlatform(config: PlatformParams): Promise<PlatformResult>;
+  filterUnavailableUsers?(users: string[]): Promise<string[]>;
 }
diff --git a/lib/workers/pr/__snapshots__/index.spec.ts.snap b/lib/workers/pr/__snapshots__/index.spec.ts.snap
index 13361625d535468ae616031ca28d7ef706a91ab6..a3941ef731a1e4d519b4f9c6880b64afac1bc5ba 100644
--- a/lib/workers/pr/__snapshots__/index.spec.ts.snap
+++ b/lib/workers/pr/__snapshots__/index.spec.ts.snap
@@ -184,6 +184,28 @@ Array [
 ]
 `;
 
+exports[`workers/pr/index ensurePr should filter assignees and reviewers based on their availability 1`] = `
+Array [
+  Array [
+    undefined,
+    Array [
+      "foo",
+    ],
+  ],
+]
+`;
+
+exports[`workers/pr/index ensurePr should filter assignees and reviewers based on their availability 2`] = `
+Array [
+  Array [
+    undefined,
+    Array [
+      "foo",
+    ],
+  ],
+]
+`;
+
 exports[`workers/pr/index ensurePr should return modified existing PR 1`] = `
 Object {
   "body": "This PR contains the following updates:\\n\\n| Package | Type | Update | Change |\\n|---|---|---|---|\\n| [dummy](https://dummy.com) ([source](https://github.com/renovateapp/dummy), [changelog](https://github.com/renovateapp/dummy/changelog.md)) | devDependencies | minor | \`1.0.0\` -> \`1.1.0\` |\\n\\n---\\n\\n### Release Notes\\n\\n<details>\\n<summary>renovateapp/dummy</summary>\\n\\n### [\`v1.1.0\`](https://github.com/renovateapp/dummy/compare/v1.0.0...v1.1.0)\\n\\n[Compare Source](https://github.com/renovateapp/dummy/compare/v1.0.0...v1.1.0)\\n\\n</details>\\n\\n---\\n\\n### Configuration\\n\\n:date: **Schedule**: \\"before 5am\\" (UTC).\\n\\n:vertical_traffic_light: **Automerge**: Enabled.\\n\\n:recycle: **Rebasing**: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.\\n\\n:no_bell: **Ignore**: Close this PR and you won't be reminded about this update again.\\n\\n---\\n\\n - [ ] <!-- rebase-check -->If you want to rebase/retry this PR, check this box.\\n\\n---\\n\\nThis PR has been generated by [Renovate Bot](https://github.com/renovatebot/renovate).",
diff --git a/lib/workers/pr/index.spec.ts b/lib/workers/pr/index.spec.ts
index 47d8de271219cdb04c422a4f6bf773f6d3d1bede..507d51cda845c769900bbd688063e28b2e740418 100644
--- a/lib/workers/pr/index.spec.ts
+++ b/lib/workers/pr/index.spec.ts
@@ -410,6 +410,16 @@ describe(getName(__filename), () => {
       expect(platform.addReviewers).toHaveBeenCalledTimes(1);
       expect(platform.addReviewers.mock.calls).toMatchSnapshot();
     });
+    it('should filter assignees and reviewers based on their availability', async () => {
+      config.assignees = ['foo', 'bar'];
+      config.reviewers = ['foo', 'bar'];
+      config.filterUnavailableUsers = true;
+      platform.filterUnavailableUsers = jest.fn();
+      platform.filterUnavailableUsers.mockResolvedValue(['foo']);
+      await prWorker.ensurePr(config);
+      expect(platform.addAssignees.mock.calls).toMatchSnapshot();
+      expect(platform.addReviewers.mock.calls).toMatchSnapshot();
+    });
     it('should determine assignees from code owners', async () => {
       config.assigneesFromCodeOwners = true;
       codeOwnersMock.codeOwnersForPr.mockResolvedValueOnce(['@john', '@maria']);
diff --git a/lib/workers/pr/index.ts b/lib/workers/pr/index.ts
index 0ddb2aab61b461aacea1f1a98e9b7ea6a424e37c..92efafb868ae10da446b31c53398f38c0871d547 100644
--- a/lib/workers/pr/index.ts
+++ b/lib/workers/pr/index.ts
@@ -33,6 +33,15 @@ async function addCodeOwners(
   return [...new Set(assigneesOrReviewers.concat(await codeOwnersForPr(pr)))];
 }
 
+function filterUnavailableUsers(
+  config: RenovateConfig,
+  users: string[]
+): Promise<string[]> {
+  return config.filterUnavailableUsers && platform.filterUnavailableUsers
+    ? platform.filterUnavailableUsers(users)
+    : Promise.resolve(users);
+}
+
 export async function addAssigneesReviewers(
   config: RenovateConfig,
   pr: Pr
@@ -41,6 +50,7 @@ export async function addAssigneesReviewers(
   if (config.assigneesFromCodeOwners) {
     assignees = await addCodeOwners(assignees, pr);
   }
+  assignees = await filterUnavailableUsers(config, assignees);
   if (assignees.length > 0) {
     try {
       assignees = assignees.map(noLeadingAtSymbol);
@@ -70,6 +80,7 @@ export async function addAssigneesReviewers(
   if (config.additionalReviewers.length > 0) {
     reviewers = reviewers.concat(config.additionalReviewers);
   }
+  reviewers = await filterUnavailableUsers(config, reviewers);
   if (reviewers.length > 0) {
     try {
       reviewers = [...new Set(reviewers.map(noLeadingAtSymbol))];
diff --git a/lib/workers/repository/init/index.spec.ts b/lib/workers/repository/init/index.spec.ts
index 63a04cbcce162416fa2cd4d482a462211eb2bb0b..71fcba1b876f99141ef30aab49568a4c60a267f6 100644
--- a/lib/workers/repository/init/index.spec.ts
+++ b/lib/workers/repository/init/index.spec.ts
@@ -1,4 +1,4 @@
-import { getName, mocked } from '../../../../test/util';
+import { getName, logger, mocked } from '../../../../test/util';
 import * as _secrets from '../../../config/secrets';
 import * as _onboarding from '../onboarding/branch';
 import * as _apis from './apis';
@@ -29,5 +29,18 @@ describe(getName(__filename), () => {
       const renovateConfig = await initRepo({});
       expect(renovateConfig).toMatchSnapshot();
     });
+    it('warns on unsupported options', async () => {
+      apis.initApis.mockResolvedValue({} as never);
+      onboarding.checkOnboardingBranch.mockResolvedValueOnce({});
+      config.getRepoConfig.mockResolvedValueOnce({
+        filterUnavailableUsers: true,
+      });
+      config.mergeRenovateConfig.mockResolvedValueOnce({});
+      secrets.applySecretsToConfig.mockReturnValueOnce({} as never);
+      await initRepo({});
+      expect(logger.logger.warn).toHaveBeenCalledWith(
+        "Configuration option 'filterUnavailableUsers' is not supported on the current platform 'undefined'."
+      );
+    });
   });
 });
diff --git a/lib/workers/repository/init/index.ts b/lib/workers/repository/init/index.ts
index 07a47f1f4cf8281503148303ec61571ba02c54f8..735e1fd44b739fe2a442e8e4375eb9456e05f47d 100644
--- a/lib/workers/repository/init/index.ts
+++ b/lib/workers/repository/init/index.ts
@@ -1,6 +1,7 @@
 import { applySecretsToConfig } from '../../../config/secrets';
 import type { RenovateConfig } from '../../../config/types';
 import { logger } from '../../../logger';
+import { platform } from '../../../platform';
 import { clone } from '../../../util/clone';
 import { setUserRepoConfig } from '../../../util/git';
 import { checkIfConfigured } from '../configured';
@@ -13,6 +14,14 @@ function initializeConfig(config: RenovateConfig): RenovateConfig {
   return { ...clone(config), errors: [], warnings: [], branchList: [] };
 }
 
+function warnOnUnsupportedOptions(config: RenovateConfig): void {
+  if (config.filterUnavailableUsers && !platform.filterUnavailableUsers) {
+    logger.warn(
+      `Configuration option 'filterUnavailableUsers' is not supported on the current platform '${config.platform}'.`
+    );
+  }
+}
+
 export async function initRepo(
   config_: RenovateConfig
 ): Promise<RenovateConfig> {
@@ -21,6 +30,7 @@ export async function initRepo(
   config = await initApis(config);
   config = await getRepoConfig(config);
   checkIfConfigured(config);
+  warnOnUnsupportedOptions(config);
   config = applySecretsToConfig(config);
   await setUserRepoConfig(config);
   config = await detectVulnerabilityAlerts(config);