Fix Gun Checks Act of 2015

This bill amends the NICS Improvement Amendments Act of 2007 to revise an eligibility condition for a state to receive a grant under the NICS Act Record Improvement Program and a waiver of the grant match requirement under the National Criminal History Improvement Program.

Specifically, it directs the Department of Justice (DOJ) to establish a four-year state implementation plan, including benchmarks, to maximize the automation and submission of mental health and criminal history records to the National Instant Criminal Back Check System (NICS). DOJ must reduce the Edward Byrne Memorial Justice Assistance (JAG) Program funding for a state that fails to comply with benchmarks.

The bill amends the Brady Handgun Violence Prevention Act to require each federal agency and department, including a federal court, to certify whether it has provided to the Federal Bureau of Investigation disqualifying records of persons prohibited from receiving or possessing a firearm.

It amends the federal criminal code and the NICS Improvement Amendments Act of 2007 to define the terms "adjudicated as a mental defective" and "committed to a mental institution."

The bill extends the Brady Handgun Violence Prevention Act background check requirements to a transfer of a firearm between private parties by prohibiting such a transfer unless a licensed importer, manufacturer, or dealer has first taken possession of the firearm for the purpose of submitting a background check.

A gun owner must report a lost or stolen firearm to DOJ and local law enforcement authorities within 48 hours of discovery.