This article documents the development and validation of a new 11-item coparenting measure specifically for low-income, nonresident fathers. Focus groups were conducted to determine various aspects of coparenting. Based on this, a scale was created and administered to 542 nonresident fathers. Analyses revealed three distinct and reliable self-perceived coparenting factors: undermining, alliance and gatekeeping. This measure was related to a substantial number of convergent and predictive validity constructs. The authors suggest these new measures for use by fatherhood programs serving low income fathers. The advance publication of the article can be found at DOI: 10.1111/famp.12331.