This variable is the unique Part D contract identifier for the beneficiary’s Part D plan of record for the year. CMS assigns an identifier to each contract that a Part D plan has with CMS. If the beneficiary was enrolled in more than one plan during the year, this is the contract number for the Part D plan in which the beneficiary was enrolled at the end of the year. The first character of the plan contract ID is a letter representing the type of plan. Source: https://bluebutton.cms.gov/resources/variables/plancntrctrec_id
This code system https://bluebutton.cms.gov/assets/ig/CodeSystem-plan-cntrct-rec-id defines the following codes: