As you probably know, Medicare Part A is hospital insurance that is generally free, while Part B is medical insurance that covers things like doctors’ services and outpatient care and has a monthly premium that varies based on your income. Part D is prescription drug coverage.
We don’t know anything about your financial situation, but in a best case scenario we think signing up for Medicare Part B (or if you already receive Social Security, not opting out) along with purchasing a separate Medicare supplement policy would provide, along with the care you receive through the VA, the most comprehensive package for your healthcare. A Medicare Advantage Plan (sometimes called Part C) would provide all of your Part A and B coverage and generally would not need to be supplemented with another insurance policy; it normally works like an HMO or PPO and typically covers prescription drugs. So, this could be a good option also.
The bottom line is that we don’t think you should limit yourself to Medicare Part A and the VA for your healthcare. You may be getting what you need from VA right now, but who’s to say that won’t change in the future? Additionally, if for some reason you’re forced to get care outside the VA, opting out could result in some major out-of-pocket expenses. Medicare Advantage plans vary in terms of pricing and what is offered, but many folks find them a cost-effective option. You can call Medicare at (800) 633-4227 to get general Medicare information and the VA at (877) 222-8387. Good luck.