Senior participation in the Supplemental Nutrition Assistance Program (SNAP) has traditionally been lower than other groups among those eligible, with historical estimates below 50 percent. We examine the impacts of state SNAP policies on program participation among low-income senior (age 60 and older) and non-senior households using data from the 2001-2014 December Current Population Survey Food Security Supplement. Our results suggest that policies designed to expand SNAP eligibility modestly increased participation among seniors but led to larger increases among non-seniors. In contrast, we find little evidence of effects of policies related to transaction costs, stigma, or outreach on either group.