Months of Part A coverage
This variable is the number of months during the year that the beneficiary had Medicare Part A coverage. (This is sometimes referred to as health insurance coverage - or Medicare HI coverage).
CCW derives this variable by counting the number of months where the beneficiary had Part A coverage (i.e., the BUYINXX variable equaled 1, A, 3, or C).
Source: CMS Common Medicare Environment (CME) (derived)