Hospital Fair Competition Act of 2005

Hospital Fair Competition Act of 2005 - Amends title XVIII (Medicare) of the Social Security Act with respect to hospital payments. Provides for the use of estimated costs rather than average charges in establishing weighting factors for diagnosis-related groups under the inpatient hospital prospective payment system.

Revises requirements for exceptions to the prohibition against certain physician self-referrals to specialty hospitals in which a physician has invested.

Exempts from the limitation on such referrals, and any liability for criminal penalties, specified arrangements between hospitals and physicians.