Did You Know: VA benefits & Medicare
If you have VA health benefits and qualify for Medicare at age 65, you can be enrolled in both plans at the same time. However, Medicare and VA benefits do not work together. Medicare does not pay for any care that you receive at a VA facility. VA health care benefits typically only cover services received at a VA facility, and for Medicare to cover your care, you must visit a non-VA facility that accepts your Medicare coverage. Having coverage through both the VA health program and Medicare gives you wider coverage and more choices of where you can be treated.
Enrollment in the VA health care system is considered creditable coverage for Medicare Part D purposes. This means that if you are enrolled in VA drug coverage, you can delay Medicare Part D enrollment without incurring a late enrollment penalty (LEP). VA prescription drug coverage is at least as good as the Medicare Part D coverage
See more: https://www.va.gov/health-care/about-va-health-benefits/va-health-care-and-other-insurance