Military Sexual Assault Prevention Act of 2013

Military Sexual Assault Prevention Act of 2013 - Prohibits any person convicted under federal or state law of rape, sexual assault, forcible sodomy, or incest from being commissioned or enlisting in the Armed Forces. Requires administrative separation from the Armed Forces, when not punitively discharged, for any member of the Armed Forces (member) on active duty, and any reserve member in an active status, who is convicted of rape, sexual assault, forcible sodomy, or an attempt thereof (covered offenses). Allows the Secretary of the military department concerned to waive such a separation in the interests of national security on a case-by-case basis.

Directs the Secretary of Defense (DOD), with respect to any charge under the Uniform Code of Military Justice (UCMJ) that alleges any of the covered offenses, to require the military department Secretaries to restrict disposition authority to specified high-command officers authorized to convene special courts-martial under the UCMJ.

States as the policy of the United States that any charge regarding the covered offenses should be disposed of by court-martial rather than non-judicial punishment or administrative action.

Requires a commanding officer who receives a report of a sexual-related offense involving a member to act upon the report within 24 hours, including by submitting the report to the next higher officer in that chain of command or referring such report to the appropriate office of special investigation.

Requires inclusion in a member's personnel service record of a substantiated complaint of a sexual-related offense. Requires commanding officer review of a member's history of substantiated sexual offenses upon a member's transfer to the new command.

Requires sexual assault forms and records to be retained for at least 50 years.

Amends the National Defense Authorization Act for Fiscal Year 2013 to require the Secretary to retain for at least 50 years certain records concerning an incident of sexual assault. (Current law mandates such retention only at the request of a member who files a specified report.)