This documented briefing presents interim findings from a RAND Center for Terrorism Risk Management Policy (CTRMP) project that aims to inform the debate over extending the Terrorism Risk Insurance Act of 2002 (TRIA), as modified in 2005. The study uses analytic tools for identifying and assessing key trade-offs among strategies under conditions with considerable uncertainty to assess three alternative government interventions in the market for terrorism insurance: TRIA; no government terrorism insurance program; and extending TRIA without other changes in the program to required insurers to offer coverage for chemical, biological, radiological, or nuclear (CBRN) attacks. The results suggest that TRIA performs better on the outcome measures examined for conventional attacks than letting the program expire but does not effectively address the risks CBRN attacks present to either businesses or taxpayers. The research also shows that requiring insurers to offer CBRN coverage without other program changes has little upside for CBRN attacks and can have significant unintended consequences in dealing with conventional attacks.