Working adults with mental illness must navigate stigma and impairment in the workplace, and these factors may affect their perceived ability to continue working in their current job. Using appraisal theory and the why try model, the current study tested for predictors (symptom severity and anticipated discrimination) of perceived work ability. Participants were recruited from Amazon’s MTurk to complete two self-report surveys, one week apart. I found that symptom severity and anticipated discrimination negatively predicted perceived work ability. Internalized stigma was not found to moderate these effects. Additionally, I found a bi-directional relationship between anticipated discrimination and symptom severity. Because direct effect hypotheses were built on the theoretical foundation of stress appraisal, a supplemental mediation analysis was included. Stress was found to partially mediate the relationships between symptom severity and perceived work ability. Results lay the groundwork for future research, including intervention studies designed to support the work ability of employees with mental illness.