diff --git a/apps/backend/src/applications/application.service.spec.ts b/apps/backend/src/applications/application.service.spec.ts
index d0d1398a..fe83f07d 100644
--- a/apps/backend/src/applications/application.service.spec.ts
+++ b/apps/backend/src/applications/application.service.spec.ts
@@ -12,6 +12,7 @@ import {
   ApplicantType,
 } from './types';
 import { DISCIPLINE_VALUES } from '../disciplines/disciplines.constants';
+import { EmailService } from '../util/email/email.service';
 
 const dummyApplication: Application = {
   appId: 1,
@@ -88,6 +89,10 @@ describe('ApplicationsService', () => {
     remove: jest.fn(),
   };
 
+  const mockEmailService = {
+    queueEmail: jest.fn().mockResolvedValue(undefined),
+  };
+
   beforeEach(async () => {
     const module: TestingModule = await Test.createTestingModule({
       providers: [
@@ -96,6 +101,10 @@ describe('ApplicationsService', () => {
           provide: getRepositoryToken(Application),
           useValue: mockRepository,
         },
+        {
+          provide: EmailService,
+          useValue: mockEmailService,
+        },
       ],
     }).compile();
 
@@ -903,4 +912,147 @@ describe('ApplicationsService', () => {
       }
     });
   });
+
+  describe('updateStatus', () => {
+    it('should update the application status and return the updated application', async () => {
+      const updatedApplication: Application = {
+        ...dummyApplication,
+        appStatus: AppStatus.ACCEPTED,
+      };
+
+      mockRepository.findOne.mockResolvedValue(dummyApplication);
+      mockRepository.save.mockResolvedValue(updatedApplication);
+
+      const result = await service.updateStatus(1, AppStatus.ACCEPTED);
+
+      expect(repository.findOne).toHaveBeenCalledWith({ where: { appId: 1 } });
+      expect(repository.save).toHaveBeenCalledWith({
+        ...dummyApplication,
+        appStatus: AppStatus.ACCEPTED,
+      });
+      expect(result).toEqual(updatedApplication);
+    });
+
+    it('should send an email when status is updated to ACCEPTED', async () => {
+      mockRepository.findOne.mockResolvedValue(dummyApplication);
+      mockRepository.save.mockResolvedValue({
+        ...dummyApplication,
+        appStatus: AppStatus.ACCEPTED,
+      });
+
+      await service.updateStatus(1, AppStatus.ACCEPTED);
+
+      expect(mockEmailService.queueEmail).toHaveBeenCalledWith(
+        dummyApplication.email,
+        'Your Application Has Been Updated',
+        expect.stringContaining('Congratulations'),
+      );
+    });
+
+    it('should send an email when status is updated to DECLINED', async () => {
+      mockRepository.findOne.mockResolvedValue(dummyApplication);
+      mockRepository.save.mockResolvedValue({
+        ...dummyApplication,
+        appStatus: AppStatus.DECLINED,
+      });
+
+      await service.updateStatus(1, AppStatus.DECLINED);
+
+      expect(mockEmailService.queueEmail).toHaveBeenCalledWith(
+        dummyApplication.email,
+        'Your Application Has Been Updated',
+        expect.stringContaining('not been accepted'),
+      );
+    });
+
+    it('should send an email when status is updated to NO_AVAILABILITY', async () => {
+      mockRepository.findOne.mockResolvedValue(dummyApplication);
+      mockRepository.save.mockResolvedValue({
+        ...dummyApplication,
+        appStatus: AppStatus.NO_AVAILABILITY,
+      });
+
+      await service.updateStatus(1, AppStatus.NO_AVAILABILITY);
+
+      expect(mockEmailService.queueEmail).toHaveBeenCalledWith(
+        dummyApplication.email,
+        'Your Application Has Been Updated',
+        expect.stringContaining('no availability'),
+      );
+    });
+
+    it('should not send an email when status is updated to IN_REVIEW', async () => {
+      mockRepository.findOne.mockResolvedValue(dummyApplication);
+      mockRepository.save.mockResolvedValue({
+        ...dummyApplication,
+        appStatus: AppStatus.IN_REVIEW,
+      });
+
+      await service.updateStatus(1, AppStatus.IN_REVIEW);
+
+      expect(mockEmailService.queueEmail).not.toHaveBeenCalled();
+    });
+
+    it('should not send an email when status is updated to ACTIVE', async () => {
+      mockRepository.findOne.mockResolvedValue(dummyApplication);
+      mockRepository.save.mockResolvedValue({
+        ...dummyApplication,
+        appStatus: AppStatus.ACTIVE,
+      });
+
+      await service.updateStatus(1, AppStatus.ACTIVE);
+
+      expect(mockEmailService.queueEmail).not.toHaveBeenCalled();
+    });
+
+    it('should throw NotFoundException when application is not found', async () => {
+      mockRepository.findOne.mockResolvedValue(null);
+
+      await expect(
+        service.updateStatus(999, AppStatus.ACCEPTED),
+      ).rejects.toThrow('Application with ID 999 not found');
+
+      expect(mockEmailService.queueEmail).not.toHaveBeenCalled();
+    });
+
+    it('should pass along repo errors during retrieval without information loss', async () => {
+      mockRepository.findOne.mockRejectedValue(
+        new Error('There was a problem retrieving the info'),
+      );
+
+      await expect(service.updateStatus(1, AppStatus.ACCEPTED)).rejects.toThrow(
+        'There was a problem retrieving the info',
+      );
+
+      expect(mockEmailService.queueEmail).not.toHaveBeenCalled();
+    });
+
+    it('should pass along repo errors during save without information loss', async () => {
+      mockRepository.findOne.mockResolvedValue(dummyApplication);
+      mockRepository.save.mockRejectedValue(
+        new Error('There was a problem saving the info'),
+      );
+
+      await expect(service.updateStatus(1, AppStatus.ACCEPTED)).rejects.toThrow(
+        'There was a problem saving the info',
+      );
+
+      expect(mockEmailService.queueEmail).not.toHaveBeenCalled();
+    });
+
+    it('should pass along email service errors without information loss', async () => {
+      mockRepository.findOne.mockResolvedValue(dummyApplication);
+      mockRepository.save.mockResolvedValue({
+        ...dummyApplication,
+        appStatus: AppStatus.ACCEPTED,
+      });
+      mockEmailService.queueEmail.mockRejectedValueOnce(
+        new Error('Failed to send email'),
+      );
+
+      await expect(service.updateStatus(1, AppStatus.ACCEPTED)).rejects.toThrow(
+        'Failed to send email',
+      );
+    });
+  });
 });
diff --git a/apps/backend/src/applications/applications.controller.spec.ts b/apps/backend/src/applications/applications.controller.spec.ts
index 30066dd7..9ffe0296 100644
--- a/apps/backend/src/applications/applications.controller.spec.ts
+++ b/apps/backend/src/applications/applications.controller.spec.ts
@@ -13,6 +13,7 @@ import { DISCIPLINE_VALUES } from '../disciplines/disciplines.constants';
 import { EmailService } from '../util/email/email.service';
 import { ApplicationValidationEmailFilter } from './filters/application-validation-email.filter';
 import { ApplicationCreationErrorFilter } from './filters/application-creation-validation.filter';
+import { NotFoundException } from '@nestjs/common';
 
 const mockEmailService = {
   queueEmail: jest.fn().mockResolvedValue(undefined),
@@ -27,6 +28,7 @@ const mockApplicationsService: Partial<ApplicationsService> = {
   findById: jest.fn(),
   create: jest.fn(),
   update: jest.fn(),
+  updateStatus: jest.fn(),
   delete: jest.fn(),
   findByDiscipline: jest.fn(),
   updateProposedStartDate: jest.fn(),
@@ -548,4 +550,97 @@ describe('ApplicationsController', () => {
       ).rejects.toThrow(errorMessage);
     });
   });
+
+  describe('updateApplicationStatus', () => {
+    it('should call updateStatus with the correct appId and status', async () => {
+      const updatedApplication: Application = {
+        ...mockApplication,
+        appStatus: AppStatus.ACCEPTED,
+      };
+
+      jest
+        .spyOn(mockApplicationsService, 'updateStatus')
+        .mockResolvedValue(updatedApplication);
+
+      const result = await controller.updateApplicationStatus(1, {
+        appStatus: AppStatus.ACCEPTED,
+      });
+
+      expect(result).toEqual(updatedApplication);
+      expect(mockApplicationsService.updateStatus).toHaveBeenCalledWith(
+        1,
+        AppStatus.ACCEPTED,
+      );
+    });
+
+    it('should call updateStatus with DECLINED status', async () => {
+      const updatedApplication: Application = {
+        ...mockApplication,
+        appStatus: AppStatus.DECLINED,
+      };
+
+      jest
+        .spyOn(mockApplicationsService, 'updateStatus')
+        .mockResolvedValue(updatedApplication);
+
+      const result = await controller.updateApplicationStatus(1, {
+        appStatus: AppStatus.DECLINED,
+      });
+
+      expect(result).toEqual(updatedApplication);
+      expect(mockApplicationsService.updateStatus).toHaveBeenCalledWith(
+        1,
+        AppStatus.DECLINED,
+      );
+    });
+
+    it('should call updateStatus with NO_AVAILABILITY status', async () => {
+      const updatedApplication: Application = {
+        ...mockApplication,
+        appStatus: AppStatus.NO_AVAILABILITY,
+      };
+
+      jest
+        .spyOn(mockApplicationsService, 'updateStatus')
+        .mockResolvedValue(updatedApplication);
+
+      const result = await controller.updateApplicationStatus(1, {
+        appStatus: AppStatus.NO_AVAILABILITY,
+      });
+
+      expect(result).toEqual(updatedApplication);
+      expect(mockApplicationsService.updateStatus).toHaveBeenCalledWith(
+        1,
+        AppStatus.NO_AVAILABILITY,
+      );
+    });
+
+    it('should throw NotFoundException when application does not exist', async () => {
+      jest
+        .spyOn(mockApplicationsService, 'updateStatus')
+        .mockRejectedValue(
+          new NotFoundException('Application with ID 999 not found'),
+        );
+
+      await expect(
+        controller.updateApplicationStatus(999, {
+          appStatus: AppStatus.ACCEPTED,
+        }),
+      ).rejects.toThrow(NotFoundException);
+    });
+
+    it('should pass along service errors without information loss', async () => {
+      jest
+        .spyOn(mockApplicationsService, 'updateStatus')
+        .mockRejectedValue(
+          new Error('There was a problem updating the status'),
+        );
+
+      await expect(
+        controller.updateApplicationStatus(1, {
+          appStatus: AppStatus.ACCEPTED,
+        }),
+      ).rejects.toThrow('There was a problem updating the status');
+    });
+  });
 });
diff --git a/apps/backend/src/applications/applications.controller.ts b/apps/backend/src/applications/applications.controller.ts
index a5e6439c..f8665823 100644
--- a/apps/backend/src/applications/applications.controller.ts
+++ b/apps/backend/src/applications/applications.controller.ts
@@ -140,9 +140,10 @@ export class ApplicationsController {
     @Param('appId', ParseIntPipe) appId: number,
     @Body() updateStatusDto: UpdateApplicationStatusDto,
   ): Promise<Application> {
-    return await this.applicationsService.update(appId, {
-      appStatus: updateStatusDto.appStatus,
-    });
+    return await this.applicationsService.updateStatus(
+      appId,
+      updateStatusDto.appStatus,
+    );
   }
 
   /**
diff --git a/apps/backend/src/applications/applications.service.ts b/apps/backend/src/applications/applications.service.ts
index 42433424..be6f4824 100644
--- a/apps/backend/src/applications/applications.service.ts
+++ b/apps/backend/src/applications/applications.service.ts
@@ -12,6 +12,21 @@ import { DISCIPLINE_VALUES } from '../disciplines/disciplines.constants';
 import { EmailService } from '../util/email/email.service';
 import { UsersService } from '../users/users.service';
 
+const STATUS_EMAIL_SUBJECTS: Partial<Record<AppStatus, string>> = {
+  [AppStatus.ACCEPTED]: 'Your Application Has Been Updated',
+  [AppStatus.DECLINED]: 'Your Application Has Been Updated',
+  [AppStatus.NO_AVAILABILITY]: 'Your Application Has Been Updated',
+};
+
+const STATUS_EMAIL_BODIES: Partial<Record<AppStatus, string>> = {
+  [AppStatus.ACCEPTED]:
+    'Hello Applicant,<br><br>Congratulations! Your application has been accepted. Please complete your forms in the MyForms tab on your applicant portal.<br><br>Thank you,<br>BHCHP Team',
+  [AppStatus.DECLINED]:
+    'Hello Applicant,<br><br>We regret to inform you that your application has not been accepted at this time.<br><br>Thank you,<br>BHCHP Team',
+  [AppStatus.NO_AVAILABILITY]:
+    'Hello Applicant,<br><br>We wanted to inform you that there is currently no availability at this time.<br><br>Thank you,<br>BHCHP Team',
+};
+
 /**
  * Escapes characters that have special meaning in HTML so a string is safe to embed in text or attributes.
  *
@@ -33,6 +48,7 @@ export class ApplicationsService {
   constructor(
     @InjectRepository(Application)
     private applicationRepository: Repository<Application>,
+    private emailService: EmailService,
   ) {}
 
   /**
@@ -193,6 +209,34 @@ export class ApplicationsService {
     return await this.applicationRepository.save(application);
   }
 
+  /**
+   * Updates the status of an application and sends a notification email
+   * if the new status is ACCEPTED, DECLINED, or NO_AVAILABILITY.
+   * @param appId The id of the application to update.
+   * @param appStatus The new application status.
+   * @returns The updated application object.
+   * @throws {NotFoundException} if the application does not exist.
+   * @throws {Error} which is unchanged from what repository or email service throws.
+   */
+  async updateStatus(
+    appId: number,
+    appStatus: AppStatus,
+  ): Promise<Application> {
+    const application = await this.findById(appId);
+
+    application.appStatus = appStatus;
+    const updated = await this.applicationRepository.save(application);
+
+    const subject = STATUS_EMAIL_SUBJECTS[appStatus];
+    const body = STATUS_EMAIL_BODIES[appStatus];
+
+    if (subject && body) {
+      await this.emailService.queueEmail(application.email, subject, body);
+    }
+
+    return updated;
+  }
+
   /**
    * Updates an application's commitment starting date with validation.
    * @param appId The id of the application to update.