The Intelligence Reform and Terrorism Prevention Act of 2004 requires that the Secretary of Homeland Security develop a plan for reliably evaluating the identity and citizenship of people entering the U.S. In response, the U.S. Customs and Border Protection CBP and U.S. Department of State are proposing a regulation specifying documentation requirements for people entering the U.S. via land borders from countries in the Western Hemisphere, referred to as the Western Hemisphere Travel Initiative WHTI-L. The White House Office of Management and Budget directs agencies to use benefit-cost analyses to evaluate proposed regulations during the regulatory review process. However, data and methods for estimating the benefits of terrorism security regulations like the WHTI-L are inadequate to support benefit-cost analysis. This report introduces a framework for using probabilistic terrorism risk modeling in a break-even analysis of a regulatory action, demonstrates an application of the framework on the regulatory analysis of WHTI-L, and discusses how this type of analysis can be further integrated into the regulatory review process.