ITIN Reform Act of 2015

Amends the Internal Revenue Code to authorize the Department of the Treasury to issue an individual taxpayer identification number (ITIN) to an individual only if such individual: (1) submits an application for an ITIN in person at an Internal Revenue Service (IRS) taxpayer assistance center with required documentation, or (2) submits an application in person outside of the United States to an IRS employee or a designee of Treasury at a U.S. diplomatic mission or consular post with required documentation. Exempts from such requirements: (1) the spouse, or the dependents, without a social security number of a taxpayer who is a member of the U.S. Armed Forces, and (2) nonresident aliens claiming tax treaty benefits.

Requires the Treasury Inspector General for Tax Administration to audit, on a biennial basis, the IRS program for issuance of ITINs pursuant to this Act and report to Congress on such audit.