diff --git a/auth/token-managers/iam-assume-token-manager.ts b/auth/token-managers/iam-assume-token-manager.ts
index 15dbfa1b..bd94d2fa 100644
--- a/auth/token-managers/iam-assume-token-manager.ts
+++ b/auth/token-managers/iam-assume-token-manager.ts
@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+import logger from '../../lib/logger';
 import { onlyOne, validateInput } from '../utils/helpers';
 import { buildUserAgent } from '../../lib/build-user-agent';
 import { IamRequestBasedTokenManager, IamRequestOptions } from './iam-request-based-token-manager';
@@ -104,6 +105,12 @@ export class IamAssumeTokenManager extends IamRequestBasedTokenManager {
     // be ignored, so we can pass the options structure to that constructor as-is.
     this.iamDelegate = new IamTokenManager(options);
 
+    // These options are used by the delegate token manager
+    // but they are not supported by this token manager.
+    this.clientId = undefined;
+    this.clientSecret = undefined;
+    this.scope = undefined;
+
     // Set the grant type and user agent for this flavor of authentication.
     this.formData.grant_type = 'urn:ibm:params:oauth:grant-type:assume';
     this.userAgent = buildUserAgent('iam-assume-authenticator');
@@ -127,4 +134,28 @@ export class IamAssumeTokenManager extends IamRequestBasedTokenManager {
 
     return super.requestToken();
   }
+
+  /**
+   * Extend this method from the parent class to erase the refresh token from
+   * the class - we do not want to expose it for IAM Assume authentication.
+   *
+   * @param tokenResponse - the response object from JWT service request
+   */
+  protected saveTokenInfo(tokenResponse): void {
+    super.saveTokenInfo(tokenResponse);
+    this.refreshToken = undefined;
+  }
+
+  /**
+   * This token manager doesn't save the refresh token but this method is still
+   * exposed by the underlying class, so we override it here to log a warning.
+   *
+   * @returns the refresh token
+   */
+  public getRefreshToken(): string {
+    logger.warn(
+      'The IamAssumeTokenManager does not store the refresh token - it will be undefined.'
+    );
+    return super.getRefreshToken();
+  }
 }
diff --git a/auth/token-managers/iam-request-based-token-manager.ts b/auth/token-managers/iam-request-based-token-manager.ts
index 52e53ab1..4c045682 100644
--- a/auth/token-managers/iam-request-based-token-manager.ts
+++ b/auth/token-managers/iam-request-based-token-manager.ts
@@ -41,11 +41,11 @@ export interface IamRequestOptions extends JwtTokenManagerOptions {
  * class be extended with specific implementations.
  */
 export class IamRequestBasedTokenManager extends JwtTokenManager {
-  private clientId: string;
+  protected clientId: string;
 
-  private clientSecret: string;
+  protected clientSecret: string;
 
-  private scope: string;
+  protected scope: string;
 
   protected refreshToken: string;
 
diff --git a/package.json b/package.json
index 4fc0a44e..e7e242ee 100644
--- a/package.json
+++ b/package.json
@@ -98,7 +98,7 @@
     "eslint:fix": "eslint . --fix",
     "eslint:check": "eslint . --cache",
     "lint": "npm run eslint:check",
-    "lint:fix": "npm run eslint:fix",
+    "fix": "npm run eslint:fix",
     "jest": "jest",
     "test": "jest test/unit/",
     "test-travis": "jest --runInBand test/unit/",
diff --git a/test/unit/iam-assume-token-manager.test.js b/test/unit/iam-assume-token-manager.test.js
index da92ae63..99979b68 100644
--- a/test/unit/iam-assume-token-manager.test.js
+++ b/test/unit/iam-assume-token-manager.test.js
@@ -63,6 +63,9 @@ describe('IAM Assume Token Manager', () => {
   RequestWrapper.mockImplementation(() => ({
     sendRequest: sendRequestMock,
   }));
+  afterEach(() => {
+    sendRequestMock.mockClear();
+  });
   afterAll(() => {
     sendRequestMock.mockRestore();
   });
@@ -210,6 +213,39 @@ describe('IAM Assume Token Manager', () => {
 
       expect(instance.userAgent).toMatch('iam-assume-authenticator');
     });
+
+    it('should store client id, secret, and scope in delegate but not in the class', () => {
+      const instance = new IamAssumeTokenManager({
+        apikey: IAM_APIKEY,
+        iamProfileCrn: IAM_PROFILE_CRN,
+        clientId: 'some-id',
+        clientSecret: 'some-secret',
+        scope: 'some-scope',
+      });
+
+      expect(instance.clientId).toBeUndefined();
+      expect(instance.clientSecret).toBeUndefined();
+      expect(instance.scope).toBeUndefined();
+      expect(instance.iamDelegate.clientId).toBe('some-id');
+      expect(instance.iamDelegate.clientSecret).toBe('some-secret');
+      expect(instance.iamDelegate.scope).toBe('some-scope');
+    });
+  });
+
+  describe('getters', () => {
+    it('should warn if user calls getRefreshToken', () => {
+      const warnSpy = jest.spyOn(logger, 'warn');
+      const instance = new IamAssumeTokenManager({
+        apikey: IAM_APIKEY,
+        iamProfileCrn: IAM_PROFILE_CRN,
+      });
+
+      instance.getRefreshToken();
+      expect(warnSpy).toHaveBeenCalledWith(
+        'The IamAssumeTokenManager does not store the refresh token - it will be undefined.'
+      );
+      warnSpy.mockRestore();
+    });
   });
 
   describe('requestToken', () => {
@@ -306,6 +342,33 @@ describe('IAM Assume Token Manager', () => {
       const accessToken = await instance.getToken();
 
       expect(accessToken).toBe(OTHER_ACCESS_TOKEN);
+
+      // Ensure the refresh token is NOT saved after `getToken` is called.
+      expect(instance.refreshToken).toBeUndefined();
+    });
+
+    it('should use client id, secret, and scope in delegate request but not the manager request', async () => {
+      const instance = new IamAssumeTokenManager({
+        apikey: IAM_APIKEY,
+        iamProfileCrn: IAM_PROFILE_CRN,
+        clientId: 'some-id',
+        clientSecret: 'some-secret',
+        scope: 'some-scope',
+      });
+
+      await instance.requestToken();
+
+      // Check the IAM delegate's request first.
+      const iamRequestOptions = getRequestOptions(sendRequestMock, 0);
+      expect(iamRequestOptions.headers).toBeDefined();
+      expect(iamRequestOptions.headers.Authorization).toBe('Basic c29tZS1pZDpzb21lLXNlY3JldA==');
+      expect(iamRequestOptions.form.scope).toBe('some-scope');
+
+      // Then, look at the second request from the IAM Assume token manager.
+      const assumeRequestOptions = getRequestOptions(sendRequestMock, 1);
+      expect(assumeRequestOptions.headers).toBeDefined();
+      expect(assumeRequestOptions.headers.Authorization).toBeUndefined();
+      expect(assumeRequestOptions.form.scope).toBeUndefined();
     });
   });
 });