This study explores how context-specific behavioral economic principles could be employed to tailor interventions to support patients’ efforts to modify day-to-day routines. Using adapted geo-ethnography techniques, interviews collected in-depth descriptions about facilitators and barriers to physical activity (PA), and contexts influencing decisions about day-to-day activities. Data were analyzed using the COM-B model for behavior change and MINDSPACE behavioral economic principles as coding frameworks. Twenty-nine patients (19 men, 10 women) aged 50–79 participated. Findings indicate patients were motivated and capable of increasing PA but were challenged to identify opportunities to adapt day-to-day routines for increasing PA. Patients described disrupting default routines, increasing commitments, changing the messenger, and introducing incentives as potentially useful behavioral economic principles to improve day-to-day decisions about increasing PA. Patients had insight into potential behavioral economic principles, although they were not previously educated, and were valuable partners in developing research and clinic-based behavioral economic intervention strategies.