Mammogram Availability Act of 2005 - Amends the Public Health Service Act and the Employee Retirement Income Security Act of 1974 (ERISA) to require a group health plan, and a health insurance issuer offering group coverage, that provides coverage for diagnostic mammographies for any woman 40 years old or older to provide no less favorable coverage for annual screening mammographies for such a woman. Prohibits related enrollment and renewal discrimination, monetary incentives to women, and penalties or incentives to providers. Applies such requirements and prohibitions to coverage offered in the individual market.