Objective: To investigate self-reported improved oral health and its mediators, and job-related outcomes, of Medicaid expansion beneficiaries in Michigan. Methods: This cross-sectional mixed-methods study of adult "Healthy Michigan Plan" (HMP) Medicaid expansion beneficiaries included qualitative interviews with a convenience sample of 67 beneficiaries enrolled for ≥6 months, a stratified random sample survey of 4,090 beneficiaries enrolled for ≥12 months; and Medicaid claims data. We examined unadjusted associations between demographic variables and awareness of dental coverage, self-reported dental care access, dental visits, and self-reported oral health; and between improved oral health and job seeking and job performance. Multivariate analysis examined factors associated with self-reported oral health improvement, adjusting for sociodemographic characteristics, prior health insurance, and having at least one dental visit claim. Results: Among surveyed beneficiaries, 60 percent received ≥1 dental visit and 40 percent reported improved oral health. Adjusted odds ratios (aOR) for improved oral health were higher for African-American beneficiaries [aOR = 1.61; confidence interval (CI) = 1.28-2.03] and those previously uninsured for ≥12 months (aOR = 1.96; CI = 1.58-2.43). Beneficiaries reporting improved oral health were more likely to report improved job seeking (59.9 percent vs 51 percent; P = 0.04) and job performance (76.1 percent vs 65.0 percent; P < 0.001) due to HMP. Interviewees described previously unmet oral health needs, and treatments that improved oral health, functioning, appearance, confidence, and employability. Conclusion: Michigan's Medicaid expansion contributed to self-reported improved oral health, which was associated with improved job outcomes. Policymakers should consider the importance of Medicaid dental coverage in