Social Security is a separate pension system, and anything he is entitled to from GM won't be included. Medicare is a deduction from Social Security; Part A covers hospitalization and is free, Part B covers doctors' bill (etc) and generally costs about $95 per month. This is not mandatory and, if he has been living outside the US, he may not have signed up for it. Generally, a doctor (assuming he accepts Medicare at all, which isn't universal) will either bill Medicare for the whole thing and then bill him for the deductible (20%) or they may want the deductible paid at the time of service. He may have supplemental insurance through GM - what we call Medigap insurance - that will pay the 20%.

Check here for general Medicare information and call 1-800-633-4227 for more specific stuff. Be prepared to get a very hard time if you try to get specific information on his account yourself - the privacy watchdogs are pretty powerful. It would be best to write down the specific information needed (i.e., "am I covered by Medicare"), wade through the morass of computer-generated questions and answers until you get to a real person, and then put him on the phone. Have his social security number, date and place of birth, and mother's maiden name available when you call.

Good luck.