Superstorm Sandy Mortgage Relief Act of 2013 - Directs the Secretary of Housing and Urban Development (HUD) and the Director of the Federal Housing Agency to carry out a program to notify mortgagors under covered mortgages of the availability of forbearance and to offer and provide such relief upon an eligible homeowner's request.

Defines "covered mortgage" as one that: (1) is secured by a one- to four-family dwelling that is the mortgagor's principal residence and is located within a major disaster area resulting from Hurricane Sandy; and (2) is insured under the National Housing Act or owned or guaranteed by the Federal National Mortgage Association (Fannie Mae) or the Federal Home Loan Mortgage Corporation (Freddie Mac).