Medicare HMO Improvement Act of 1999

Medicare HMO Improvement Act of 1999 - Amends part C (Medicare+Choice) of title XVIII (Medicare) of the Social Security Act with regard to contracts with Medicare+Choice organizations to: (1) provide for extension of the initial Medicare+Choice contract period from one year to three years; and (2) require termination of any contract with an organization that terminates coverage for any part of a metropolitan statistical area (or a New England County Metropolitan Area). Authorizes the Secretary of Health and Human Services to delay the effectiveness of a Medicare+Choice organization's termination of its plan with respect to all individuals in an area, if: (1) the termination would cause an imminent and serious health risk to enrollees; (2) the termination would result in a significant reduction in the Medicare+Choice plans available in the area affected; or (3) the chief executive officer of the State in which the termination occurs requests such a delay. Provides for continuity of care, for a limited period, in certain cases of involuntary termination (other than for cause) of an individual's enrollment with a Medicare+Choice plan.