Background: Outcome expectancy (OE) is the belief about specific consequences that may result due to certain behaviors. OE may be linked to sexual compulsivity (SC), however, studies examining disparities by age group and sexual orientation among MSM living with HIV are lacking. Objective: To assess disparities by age and sexual orientation in the association between OE and SC among MSM living with HIV. Methods: Data were obtained from 338 MSM living with HIV. Interactions between OE and age, and between OE and sexual orientation were tested. Multiple linear regression was used to determine the associations between self-efficacies for condom use, disclosure, and negotiation of safer sex practices, and SC for gay and bisexual men separately, and for MSM aged 18-34, 35-49 and ≥50 years. Results: No statistically significant differences emerged in the associations between OE and sexual compulsivity by sexual orientation. However, disparities in the association between OE and SC were seen by age. After adjusting for race/ethnicity, education, income, employment, and time since diagnosis, among MSM aged 18-34 and 35-49, every unit increase in OE for condom use was associated with a one-unit decrease in SC (β: -1.02; 95% CI: -1.72, -0.31, β: -1.00, 95% CI: -1.51, -0.50, respectively). Among MSM aged 35-49, every unit increase in OE for HIV disclosure and negotiation of safer sex practices was also associated with a one-unit decrease in SC. Conclusions: Intervention programs aimed at reducing SC among MSM living with HIV are warranted and should address OEs and consider age differences.