Keep Student Loans Affordable Act of 2013 - Amends title IV (Student Assistance) of the Higher Education Act of 1965 to extend the 3.4% interest rate on Direct Stafford loans first disbursed to undergraduate students between July 1, 2011, and July 1, 2013, to Direct Stafford loans first disbursed to undergraduate students between July 1, 2011, and July 1, 2014.

Amends the Internal Revenue Code to modify rules for required distributions from tax-exempt pension plans to an employee who dies before such employee's entire interest is distributed to require such interest to be distributed within five years after the death of such employee, subject to exceptions for an eligible designated beneficiary and surviving spouse of such employee. Defines "eligible designated beneficiary" to include a disabled or chronically-ill individual. Exempts from such modification a binding annuity contract in effect on the enactment date of this Act.