Breast Density and Mammography Reporting Act of 2013 - Amends the Public Health Service Act to require mammography facilities to include information regarding the patient's individual measure of breast density in both the written report of the results of a mammography examination provided to the patient's physician and the summary of that written report given to patients. Requires the summary to: (1) convey the patient's risk of developing breast cancer associated with below, above, and average levels of breast density; and (2) include language communicating that individuals with more dense breasts may benefit from supplemental screening tests and should talk with their physicians about any questions or concerns regarding the summary.