Medicare: Decoding the Parts and Plan Letters

People often mix up parts, plans, and abbreviations, but the structure gets clearer when coverage is grouped into Original coverage, supplements, drug coverage, and alternatives.
Everyone starts with Part A and Part B, called Original coverage, then chooses whether to keep only that coverage, add supplements, or elect Advantage.
Keeping only Part A and Part B leaves unlimited out-of-pocket costs. Adding a supplement and Part D can limit costs to the $283 deductible.
Part C is a package, not a part, combining hospital, medical, and drug coverage. Plans use abbreviations like PPO, HMO, SNP, MSA, and PFFS.
Helpful rule: parts mean core coverage, single letters mean supplement policies with Parts A and B, and longer abbreviations mean Advantage plans.