Nonmarital childbearing in the United States increased from the 1940s to the 1990s, peaked in 2007-2008, and declined in 2013 (1-3). In 2013, the nonmarital birth rate was 44.8 births per 1,000 unmarried women aged 15-44. Using data from the National Survey of Family Growth (NSFG), this study examines nonmarital first births reported by fathers aged 15-44. This report presents trends in nonmarital first births by father's age at birth and Hispanic origin and race. Given increases in births occurring in cohabiting unions (2,4,5), first births within cohabitation are also examined.