In the United States, posttraumatic stress disorder (PTSD) disparities among sexually minoritized men (SMM) are well-documented, but diverse PTSD symptom manifestations and related vulnerabilities in this group are understudied. From October 2020 to January 2021, we collected cross-sectional demographic, HIV status, sexual behavior, and mental health data from 6319 trauma-exposed SMM in the American Men's Internet Survey. We used latent class analysis, multinomial logistic regression, and the Bolck-Croon-Hagenaars method to identify PTSD symptom classes, associations with class membership, and prevalence of serodifferent condomless anal sex with a male partner, respectively. Mean age was 33 years; most participants identified as gay (n = 4820, 76.3%) and non-Hispanic White (n = 3829, 60.6%). Classes included Intrusive-Avoidant (n = 1086, 17.2%; moderate/ high intrusive thoughts, related discomfort, trauma-reminder avoidance), Dysphoric-Inattentive (n = 1230, 19.5%; moderate/high negative beliefs, anhedonia, concentration problems), Pervasive (n = 1471, 23.3%; high on all symptoms), and Resistant (n = 2532, 40.1%; low on all symptoms). Non-Hispanic Black (aOR = 1.77, 95% CI = 1.35, 2.33) and multiracial identity (aOR = 1.48, 95% CI = 1.03, 2.13) were associated with IntrusiveAvoidant class membership. Unknown (aOR = 1.24, 95% CI = 1.01, 1.52) and positive HIV status (aOR = 1.56, 95% CI = 1.16, 2.09) were associated with Pervasive class membership. Housing instability, mental distress, and suicidal ideation were associated with membership in each symptomatic class. Serodifferent condomless anal sex was higher in the Pervasive (23.9%, p < 0.001) and Intrusive-Avoidant (21.8%, p = 0.008) classes relative to the Resistant class (16.5%). Improving the response to PTSD and related vulnerabilities among SMM merits combined trauma-focused, sexual risk-reduction approaches tailored to symptom profiles.