Patients Right to Know Act of 2013 - Amends the Public Health Service Act to require health plans to include in their annual summary of benefits and coverage explanations: (1) the annual fee on health insurance providers under the Patient Protection and Affordable Care Act, (2) the annual fees imposed on health insurance policies, (3) required contributions by health plans to the reinsurance program, (4) user fees on health plans participating in health insurance exchanges, (5) payments by health plans whose costs are lower than the target amount (premiums collected minus administrative costs), and (6) charges assessed by states on health plans whose enrollees have a lower actuarial risk than the average actuarial risk of all enrollees in a state. Allows such costs to be calculated separately for individual, small group, or large group markets.

Requires the Comptroller General (GAO) to study the methods of calculating the impact on average premium costs associated with: (1) guaranteed issuance of coverage and community rated premiums, (2) limitations on age rating, (3) required coverage of women's preventive services, and (4) the requirement that plans cover at least 60% of the actuarial value of essential health benefits.