Trends in Medicare supplemental insurance and prescription drug coverage, 1996-1999.

Medicare Current Beneficiary Survey (MCBS) Access to Care data indicate a five-percentage-point decline in the share of Medicare beneficiaries having Medigap coverage between 1996 and 1999; this was matched by a commensurate rise in the share enrolled in Medicare HMOs, contributing to an increase in the percentage with drug coverage. During this period, high-income beneficiaries, and to a lesser extent healthier and rural beneficiaries, experienced greater net declines in supplemental coverage and smaller relative gains in drug coverage, compared with others. By fall 1999, 38 percent of beneficiaries lacked drug coverage, based on point-in-time estimates. This is much higher than previous estimates that measured beneficiaries' drug coverage at any time during the calendar year. Many of Medicare's most vulnerable beneficiaries--rural (50 percent), near-poor (44 percent), and oldest old (45 percent)--were most likely to lack drug coverage in the fall of 1999.