The national opioid crisis continues to intensify, despite the fact that opioid use disorder (OUD) is treatable and opioid overdose deaths are preventable through first-line treatment with medications for opioid use disorder (MOUD). This study identifies and categorizes payment-related barriers that impact MOUD access and retention from both the provider and patient perspectives and provides insight into how these barriers can be addressed. We performed a critical review of the literature (peer-reviewed studies and relevant documents from the gray literature) to identify payment-related access and retention barriers to MOUD. We used the results of this review to develop an analytic framework to understand how payment impacts MOUD access and retention for both providers and patients. In addition, we reviewed action plans developed by Massachusetts communities that participated in the Healing Communities Study (HCS) to analyze which payment-related barriers were addressed through the study. We identified 18 payment-related barriers that patients or providers face when initiating or continuing MOUD with either methadone or buprenorphine in Opioid Treatment Programs (OTP) and non-OTP settings. Patient-related barriers mainly relate to health insurance coverage or the design of health plans (e.g., cost sharing, covered benefits) resulting in direct (medical and non-medical) and indirect costs that can affect both access and retention, especially as they relate to services provided in OTPs. Provider-related barriers include low reimbursement and administrative burden and are most likely to impact access to MOUD. Evidence-based strategies to expand MOUD as part of the HCS in Massachusetts targeted about half of the patient and provider payment-related barriers identified. Patients and providers face an array of payment-related barriers that impact access to and retention on MOUD, most of which relate to inadequate health insurance coverage, features of health plans, and key federal and state policies. As new regulatory policies are enacted that expand access to MOUD, such as greater flexibility in OTPs and MOUD delivered via telehealth, it will be important to align these delivery changes with payment reform involving payers, providers, and policymakers.