This study examined how immigrant status and socioeconomic status influence racial self-classification among U.S. Latinx adults aged eighteen and older across multiple nationalities. Using data from the 2010–2018 National Health Interview Survey, we analyzed a nationally representative sample of Mexican, Cuban, Puerto Rican, Dominican, and Central/South American adults (N = 41,133) who identified as White, Black, or Another race. Socioeconomic status was measured using a composite index of income-to-poverty ratio, education, employment status, and homeownership. Multinomial logistic regressions and average marginal effects revealed significant heterogeneity in examined predictors of racial identity. U.S.-born Latinx adults, particularly Puerto Ricans and Central/South Americans, had higher probability of identifying as Black compared to recent immigrants. Latinx adults with low and middle socioeconomic status backgrounds were more likely to identify as Black or Another race across most nationality groups. Findings highlight the complexity of Latinx racial identity, whereby Latinxs may experience racialization differently depending on indicators of acculturation and socioeconomic status. The inclusion of multidimensional measures of race, such as skin color and street race, in future research is needed to better understand Latinx racial identity formation. Findings inform interventions to address race-related stress and anti-Blackness, particularly among AfroLatinx populations, and provide considerations for improving race data collection practices, such as those impacted by recent federal policy changes to the U.S. Census.