Medicaid Program Integrity Act of 2013 - Amends title XIX (Medicaid) of the Social Security Act with respect to the option a state has, when determining an individual's Medicaid eligibility for long-term care assistance, to change the $500,000 maximum allowable equity interest of the individual in his or her home. Gives states the further option to reduce the maximum allowable home equity interest below $500,000 but not below $50,000. Requires indexed inflation adjustments to the state-selected alternative maximum beginning in 2014.

Revises the general maintenance of effort requirement that a state maintain Medicaid eligibility standards no stricter than those in effect when the Patient Protection and Affordable Care Act (PPACA) was enacted until the state health insurance exchange required by such Act is operational. Declares that such maintenance of effort requirement shall not apply to changes in eligibility standards for medical assistance for long-term care services, so long as such changes would have been permitted under the law as in effect before the enactment of PPACA.