Medicare Advantage is an alternative to Original Medicare, and it combines Medicare Part A and Part B into one, privately-administered plan. An MAPD also includes Part D coverage, so a person who selects an MAPD would have Parts A, B, and D coverage, all under one plan.
Note that in addition to the Medicare Advantage premiums, the enrollee still has to pay Part B premiums directly to the government. In most cases, this is in the form of a deduction from their Social Security check.
Almost all Medicare Advantage plans are MAPDs: 88 percent of Medicare Advantage plans included prescription drug coverage as of 2017.