Small Business Health Insurance Affordability Act of 2005 - Amends the Internal Revenue Code to: (1) allow certain small employers (employers with between two and 50 employees) a business tax credit for payment of employee health insurance costs; (2) allow private foundations to make grants to a qualified health benefit purchasing coalition. Defines "qualified health benefit purchasing coalition" as a private non-profit corporation which sells health insurance to employers through State licensed health insurance issuers.
Directs: (1) the Secretary of Health and Human Services to award demonstration grants to States to develop innovative ways to increase access to health insurance through market reforms and other means; and (2) the Small Business Administration (SBA) to award grants to States, local governments, and nonprofit organizations to provide information to small employers about the benefits of health insurance.