This cross-sectional study examines the composition, variation, and factors associated with health care contact days among older adults in traditional Medicare. Using 2019 Medicare Current Beneficiary Survey data linked to claims, the study found that older adults spent an average of 17.3 ambulatory contact days (SD, 22.1) and 20.7 total contact days (SD, 27.5) in the year. These contact days were primarily ambulatory, including primary care visits, specialty care visits, tests, imaging, procedures, and treatments. Factors associated with more ambulatory contact days included younger age, female sex, White race, non-Hispanic ethnicity, higher income, higher education, urban residence, and more chronic conditions. The study highlights the substantial impact of ambulatory care on older adults' lives and suggests opportunities for optimization through care coordination, such as reducing unnecessary care and consolidating services. The findings also indicate that variation in contact days is not fully explained by clinical need, suggesting the need for further exploration of clinician and health system practices.This cross-sectional study examines the composition, variation, and factors associated with health care contact days among older adults in traditional Medicare. Using 2019 Medicare Current Beneficiary Survey data linked to claims, the study found that older adults spent an average of 17.3 ambulatory contact days (SD, 22.1) and 20.7 total contact days (SD, 27.5) in the year. These contact days were primarily ambulatory, including primary care visits, specialty care visits, tests, imaging, procedures, and treatments. Factors associated with more ambulatory contact days included younger age, female sex, White race, non-Hispanic ethnicity, higher income, higher education, urban residence, and more chronic conditions. The study highlights the substantial impact of ambulatory care on older adults' lives and suggests opportunities for optimization through care coordination, such as reducing unnecessary care and consolidating services. The findings also indicate that variation in contact days is not fully explained by clinical need, suggesting the need for further exploration of clinician and health system practices.