Medicare Beneficiaries' Choice Stabilization 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 provide for: (1) establishment of a floor for Medicare+Choice payment rates after applying risk-adjustment methodology; (2) elimination of budget neutrality adjustment for 2001 and 2002; (3) an increase in national per capita Medicare+Choice growth percentage in 2001 and 2002: (4) election by a Medicare+Choice organization to apply an area- specific percentage of 50 percent and a national percentage of 50 percent for 2001 and 2002 rather than the rate currently applicable for 2002 in determining the blended capitation rate used in determining the calculation of annual Medicare+Choice capitation rates; (5) an increased update for payment areas with only one or no Medicare+Choice contracts; (6) higher negotiated rates in certain Medicare+Choice payment areas below national average; and (7) a ten year phased-in risk adjustment based on data from all settings.

Delays from July to November 2000 the deadline for withdrawing the offer, or rescinding the withdrawal, of Medicare+Choice plans for 2001.

Amends SSA title XVIII part C to Medicare+Choice program data collection requirements with regard to: (1) issuance of encounter data submission requirements; (2) post- stabilization guidelines; and (3) on-line enrollment.

Prohibits the Secretary from making any changes in the enrollment and disenrollment instructions and related materials (including operational policy letters and evidence of coverage) under Medicare+Choice between enactment of this Act and January 1, 2002, except as may be specifically and only required to comply with a change in statute.