Nativity status/length of stay in the US has been found to be associated with obesity. However, little work has examined the role of nativity status/length of stay in excessive gestational weight gain (EGWG) in adolescents. This study utilized New York City Department of Health and Mental Hygiene birth certificate data in a cross-sectional analysis of 15,715 singleton births to primiparous teen mothers (12-19 years) between 2008 and 2010. Nativity and length of stay in the United States (US) were obtained from birth certificates. EGWG was calculated using weight at delivery and pre-pregnancy weight. Prevalence ratios were calculated through generalized estimating equations to assess the strength of the association between nativity status/length of US residence and EGWG. For US-born teens, 43 % gained more weight than recommended as compared to 32 % for foreign-born teens who have lived in the US for less than 5 years (FB <5 years). Following adjustment for maternal demographics and other factors, US-born teens (adjusted prevalence ratios (APR) (CI) 1.26 [1.18,1.34]), FB 10+ years (APR (CI) 1.17 [1.07,1.28]), and FB 5-10 years (APR (CI) 1.11 [1.01,1.21]) were more likely to have gained weight excessively as compared to FB <5 years. US-born teens and FB teens that have been in the US longer than 5 years are more likely to gain weight excessively during pregnancy as compared to teens with fewer than 5 years in the US. These results identify a critical period when adolescents are in frequent contact with health care providers and can receive counseling regarding healthy weight gain.