BACKGROUND: Despite its importance to care and outcomes for older adults, functional status is seldom routinely measured in primary care. Understanding patient perspectives is necessary to develop effective, patientcentered approaches for measuring function, yet we know little about patient views on this topic. OBJECTIVE: To examine patient and caregiver perspectives on measuring activities of daily living (ADLs) and instrumental ADLs (IADLs). DESIGN: Qualitative study using semi-structured interviews. PARTICIPANTS: Twenty-eight patients aged 65 or older and five caregivers in primary care clinics at one Veterans Affairs Medical Center. APPROACH: We conducted interviews to elicit patient and caregiver perspectives on the importance of measuring function, including preferences for method of screening and assessment, wording of questions, and provider communication style. We analyzed interviews using qualitative thematic analysis. KEY RESULTS: We identified several themes related to measuring function in primary care. First, most participants reported that measuring function is part of quality, holistic care. However, a minority of participants noted that discussing function, especially IADLs, was not medically relevant. Second, in terms of preferences for measuring function, participants noted that interdisciplinary approaches to measuring function are optimal and that face-to-face assessment is most "intimate" and can prompt reflection on one's limitations. However, some participants indicated that self-assessment is less invasive than inperson assessment. Third, participants had varied preferences regarding communicating about function. Participants noted that asking about difficulty with activities versus need for help are distinct and complementary concepts and that providing context is essential when discussing sensitive topics such as functional decline.CONCLUSIONS: Most patients and caregivers reported that measuring function was important, preferred faceto-face assessment, and emphasized the importance of providing context when asking about function. These findings suggest that incorporating patient and caregiver preferences for measuring function can improve satisfaction and experience with functional assessment in primary care.