Puerto Rico Medicare Part B Equity Act of 2013 - Amends title XVIII (Medicare) of the Social Security Act to repeal the exclusion of residents of Puerto Rico from deemed enrollment under part B (Supplementary Medical Insurance Benefits) and thus apply it to them.

Directs the Secretary of Health and Human Services (HHS) to provide for a special seven-month enrollment period for such residents.

Requires recalculation of the late enrollment penalty to 15% of the usual penalty for residents of Puerto Rico who are current enrollees or who enroll during a specified transition period.