["Journal for the Scientific Study of Religion, EarlyView. ", "\nAbstract\nThe fourth wave of the National Congregations Study (NCS‐IV) was conducted in 2018–2019 with a nationally representative sample of congregations from across the religious spectrum. The NCS‐IV included a fresh cross‐section of congregations generated in conjunction with the 2018 General Social Survey and a panel of congregations that participated in the third NCS wave. Data were collected via a 65‐minute interview with one key informant from 1,262 congregations. The cooperation rate was 74 percent; the conservatively calculated response rate was 69 percent. Information was gathered about multiple aspects of congregations’ social composition, structure, activities, leadership, and programming. Approximately two‐thirds of the NCS‐IV questionnaire replicates items from previous NCS waves. This introduction to the NCS‐IV symposium describes NCS‐IV methodology and special features of the new data. The three symposium articles present NCS‐IV results about congregations’ political activities, racial and ethnic composition, and worship practices.\n"]