National Congregations Study (NCS)The National Congregations Study surveys a representative sample of America’s churches, synagogues, mosques, and other local places of worship. The NCS is based on in-depth interviews with congregational leaders in 1998, 2006-2007, 2012, and 2018-2019. It gathers information about worship, programs, staffing, community activities, demographics, and many other characteristics of American congregations.