Original Medicare Part A and Part B generally provide consistent coverage across all 50 states. They usually don’t have networks, so long as physicians, practices and facilities broadly accept Medicare assignment.
Since Medicare Advantage plans are partly underwritten by private insurance companies, though, the insurer-underwritten portion frequently doesn’t have as broad acceptability. The private portion only often has a provider network. A network may be national, regional or statewide, and it’s common for some providers to not participate.
Seniors should consider the network when selecting a plan, as the costs for in-network and out-of-network care can vary greatly.