If you are someone who is trying to figure out how to use your health coverage provided by your employer to pay for your mental health or substance use services – this sheet is for you. Your health plan or health coverage is sometimes called health insurance. Parity of mental health and substance use benefits There is now a United States law stating that certain health plans must cover mental health and substance use (MH/SU) services comparably (in a similar way) to medical and surgical care, or what most people refer to as physical health. 1 Many simply refer to the requirement of the law as parity, as we do here.