According to the Frequently Asked Questions page on UnitedAmerican.com, its group retiree plans are available in all 50 states. However, as of October 2015, the company is not taking any new enrollments, as it explains on UAMedicarePartD.com. United American may open part D enrollment again in the future.
Part A of Medicare is for hospital benefits and is available for anyone who has earned enough Social Security and Medicare credits through working, notes Medicare Interactive. Part B deals with doctor visits and charges an additional premium. Part C allows for private insurance plans to administer Medicare benefits. Part D, such as what United American provides, is only for prescription coverage.