Any agency accepting Federal funds (and that includes Medicare and Medicaid) must provide interpreters for the Deaf. That means, it is the responsibility of the hospital or doctor to hire and pay for the terp.
http://www.nad.org/site/pp.asp?c=foINKQMBF&b=92505
It is the Deaf patient's responsibility to let the hospital or doctor know that you will require a terp. The patient should give the hospital as much advance notice as possible. Most Deaf patients inform the hospital at the same time that the appointment is made.
Public schools and colleges are responsible for hiring and paying for terps for the students. Schools providing terps for Deaf parents is not always clearly defined. Some schools do that, no problem. Some schools use the education terps from their staff; sometimes OK, sometimes not. Some schools think it is OK for the hearing child to interpret for the Deaf parent. WRONG!
Government agencies must provide terps (Social Security office, Federal Civil Service, VR offices, etc.) for their employees and clients.
http://www.usdoj.gov/crt/ada/adahom1.htm
Private companies; it depends. The size of the company, whether or not it does government contract work, etc.
http://www.nad.org/site/pp.asp?c=foINKQMBF&b=99540
