Employers, state and local government agencies, and places of public accommodation must ensure that their communications with individuals with disabilities are as effective as communication with others.  In order to provide equal access, these groups are required to provide auxiliary aids and services that promote effective communication.

Examples of auxiliary aids and services include, but are not limited to, qualified interpreters, captioning, TTYs, large print materials, Braille materials, and computer software.

Q:  Am I always entitled to an interpreter?

A:  Sign language interpreters may be required when the information being communicated in a transaction is complex or is exchanged for a long period of time.  An interpreter is not always required for all communication situations.  Factors to be considered when deciding if the use of an interpreter is appropriate can include the context of the conversation, the number of people involved, and the importance of the communication.

For more details…

DOJ  opinion letters