Combination Drug Development Incentive Act of 2013 - Amends the Federal Food, Drug, and Cosmetic Act with respect to the five-year bar on a new drug application (or abbreviated drug application) by anyone that has not obtained a right of reference or use from the original and approved drug approval applicant by or for whom investigations under the original, subsequently approved application were conducted.

Applies this five-year bar, and the requirement of a grant of a right of reference or use, with respect to an approved drug application (or abbreviated drug application) if: (1) the application contains reports of new clinical investigations (other than bioavailability studies) essential to the approval of the application and conducted or sponsored by the applicant, (2) the application is for a drug which contains a combination of active ingredients (combination drug), and (3) no such combination of active ingredients has been approved in any other application.