Food stamp participation rates plummeted from 75 percent in 1994 to 59 percent in 2000. In response to plummeting participation rates, and with the new flexibility brought about by the 1996 federal welfare reforms, many states are re-engineering their programs to improve accessibility. States are extending office hours, establishing automated call centers, and improving outreach, among other changes. But not all program changes are geared toward increasing participation rates. States have strong financial incentives to keep Food Stamp Program certification error rates low, a goal that often runs counter to improving participation rates. States are making policy decisions, which have strong implications for Food Stamp Program participation decisions, without the benefit of knowing the factors that make some eligible working persons choose to participate and others choose not to participate. This study examines how low-income households' employment characteristics influence Food Stamp Program participation.