Small Business Health Insurance Promotion Act of 2005

Small Business Health Insurance Promotion Act of 2005 - Amends the Internal Revenue Code to allow certain small employers (not more than 50 employees) a business tax credit equal to 50 percent of amounts paid by such employers for the health care coverage of their employees under a qualified health pooling arrangement. Limits the period during which the tax credit may be taken to four years from the date the employer begins participating in a qualified health pooling arrangement. Defines "qualified health pooling arrangement" as a national or state arrangement that provides health benefits coverage substantially similar to that of the four largest health benefit plans offered to Federal employees.

Directs the Secretaries of Health and Human Services and Labor to provide for the offering and oversight of qualified State and national health pooling arrangements and to conduct a study, through the Institute of Medicine of the National Academy of Sciences, of the operation of such arrangements.