Dynamics in drug coverage of Medicare beneficiaries: finders, losers, switchers.

Although the vast majority of elderly Americans have the stability of basic Medicare benefits, Medicare alone offers no protection from the vicissitudes of the market for outpatient prescription drugs. This paper analyzes the sources and stability of prescription coverage maintained by Medicare beneficiaries in 1995 and 1996. The results show that fewer than half of all beneficiaries had continuous drug coverage over this period, while nearly a third gained, lost, or had spells without coverage.