The Monetary Choice Questionnaire (MCQ) is one of the most commonly used measures to assess delay discounting of reward. Reliable measurement by the MCQ is necessary for use in experimental settings or prognostic validity within clinical contexts. The present analysis expands prior work to evaluate temporal reliability and stability over an extended period, including repeated measurements, a larger and more broadly representative sample, and demonstrations of covariation with clinically significant health behaviors (e.g., cigarette use, COVID-19 vaccination, body mass index). Participants (