Medicare+Choice Rescue Act of 2000 - Amends part C (Medicare+Choice) of title XVIII (Medicare) of the Social Security Act (SSA), with respect to payments to Medicare+Choice organizations, to: (1) increase the national per capita Medicare+Choice growth percentage in 2001 and 2002; (2) eliminate the reduction in Medicare+Choice payment rates by budget neutrality adjustments; (3) establish a payment floor for Medicare+Choice plans, as well as an additional floor for an annual increase in Medicare+Choice capitation rates; and (4) apply a budget neutrality principle to the new Medicare+Choice risk adjustment methodology.

Directs the Secretary of Health and Human Services to correct for misestimates in the national per capita Medicare+Choice growth rate by providing for an increase by 3.6 percent in the amount of payment otherwise applicable to Medicare+Choice organizations offering Medicare+Choice plans in 2001. Limits retroactive adjustments.

Amends Medicare part C to provide for: (1) continuous open enrollment and disenrollment under Medicare+Choice and Medicare supplemental policy (Medigap) provisions on coverage election periods; and (2) variations in premiums and benefits under Medicare+Choice within counties.

Directs the Secretary of Health and Human Services to provide that risk-adjustment methodology under Medicare+Choice, insofar as it makes adjustments to capitation rates for health status, shall not only apply to ten percent of 1/12 of the annual Medicare+Choice capitation rate in the case of an eligible individual who is institutionalized until the first year in which the Secretary implements a modification of such methodology based on health status so that such methodology includes medical diagnostic factors from all provider settings (including hospital and nursing facility settings).