Social Security Number Misuse Prevention Act - Amends the federal criminal code to prohibit the display, sale, or purchase of Social Security numbers without the affirmatively expressed consent of the individual, except in specified circumstances. Directs the Attorney General to study and report to Congress on all the uses of Social Security numbers permitted, required, authorized, or excepted under any federal law, including the impact of such uses on privacy and data security.

Establishes a public records exception to the prohibition. Directs the Comptroller General to study and report to Congress on Social Security numbers in public records. Grants the Attorney General rulemaking authority to enforce this Act's prohibition and to implement and clarify the permitted uses occurring as a result of an interaction between businesses, governments, or business and government.

Amends title II (Old Age, Survivors, and Disability Insurance) of the Social Security Act (SSA) to prohibit: (1) the use of Social Security numbers on checks issued for payment by governmental agencies; and (2) inmate access to Social Security account numbers.

Prohibits a commercial entity from requiring an individual to provide a Social Security number when purchasing a commercial good or service or denying an individual the good or service for refusing to provide that number, with exceptions. Establishes civil and criminal penalties.

Extends civil monetary penalties for misuse of a Social Security number.

Provides for: (1) criminal penalties under SSA title II for the misuse of a Social Security number; (2) civil actions and civil penalties against persons who violate this Act; and (3) federal injunctive authority with respect to any violation by a public entity.