SNAP is the largest of the 15 domestic food and nutrition assistance programs overseen by USDA's Food and Nutrition Service (FNS). FNS jointly administers SNAP with the states. FNS pays the full cost of SNAP benefits and pays approximately half of states' administrative costs. FNS is also responsible for promulgating program regulations and ensuring that state officials administer the program in compliance with program rules. States administer the program by determining whether households meet the program's eligibility requirements, calculating monthly benefits for qualified households, and issuing benefits to participants.