In recent years, several studies have evaluated the effect of Medicaid insurance status on total shoulder arthroplasty (TSA) outcomes and have presented discordant findings. The purpose of this study is to determine if Medicaid status is an independent predictor of all-cause complications, readmission, revision, and mortality following elective primary TSA using a large, national administrative claims database. The Nationwide Readmissions Database (NRD) was queried to identify patients who underwent elective primary TSA from 2016 to 2020. Patients were propensity score matched in a 1:1 proportion based on age, sex, and discharge weight, yielding 15,374 Medicaid cases and 15,448 control cases. Patient demographic and discharge information, preoperative comorbidities, and postoperative outcomes were compared with bivariate analysis. Binary logistic regression was performed to account for the influence of variables other than Medicaid status on postoperative outcomes. Medicaid patients had higher rates of preoperative comorbidities, higher Charlson-Deyo Comorbidity Index scores, and lower household incomes than matched controls. Compared to controls, Medicaid patients undergoing TSA had higher odds of adverse clinical outcomes, including all-cause complications, readmission, and mortality within 180 days, along with other specific medical and implant-related complications including broken hardware, dislocation, prosthetic loosening, and surgical site infection. Medicaid status was independently predictive of increased rates of all-cause complications within 180 days, readmission within 180 days, dislocation, pneumonia, sepsis, and decreased rates of prosthetic loosening. Medicaid patients had an increased mean cost of $1,396 and increased mean length of stay of 0.4 days. Medicaid status was independently predictive of readmission, complications, and mortality within 180 days of primary TSA, as well as other specific medical and surgical complications. Medicaid patients experience higher admission costs and longer hospital stays compared to those with other insurance types. Medicaid status is a risk factor for adverse clinical outcomes, and orthopedic surgeons need to consider the multitude of disparities that Medicaid patients experience when determining surgical options, treatment plans, and hospital disposition.