To be more precise, if you are an individual, your income can not be more then $10,400 while a family of three should not exceed the established income of $17,600 per year. If your income is within the guidelines that Merck has established your next step is to fill out the program enrollment forms. These forms are readily available from the company’s website or by a quick telephone call to the company directly. After you have filled out the enrollment form you should take it to your family doctor for his approval and signature, Patient Assistance Program.