Medigap

Private supplemental insurance that fills the gaps in Original Medicare: coinsurance, copays, and the lack of an annual out-of-pocket maximum. Standardized into ten plan letters (A, B, C, D, F, G, K, L, M, N) where Plan G is the most popular for people newly eligible after 2020. Premiums vary by state, age, and underwriting. The one-time guaranteed-issue right at age 65 is the easiest entry; later you may be denied or charged more for pre-existing conditions. HSA dollars cannot pay Medigap premiums (Medicare Advantage and Part D premiums can be paid from HSA).