Introduction: Among individuals with low income, cost is a well-established barrier to medication adherence. Spending less on basic needs to pay for medication is a particularly concerning cost-coping strategy and may be associated with worse health outcomes. The aims of this study were (1) to describe the demographic and health status characteristics of those who report spending less on basic needs to pay for medication, and (2) to understand the associated psychosocial and financial challenges of these individuals.Methods: We administered a survey to primarily low-income adults (n = 270) in St. Louis, MO, as part of a larger study from 2016 to 2018. Logistic regression was used to model odds of reporting spending less on basic needs to pay for medication.Results: Spending less on basic needs to pay for medication was significantly more likely in individuals with fair or poor health status, greater number of chronic conditions, greater medication expenditure, and difficulty paying bills. Individuals who spent less on basic needs were less likely to be fully adherent to their medication regimen.Conclusions: Screening for unmet basic needs and offering referrals to social safety net programs in the primary care setting may help patients achieve sustainable medication adherence.