This study quantifies the time patients with cancer spend on ambulatory appointments, including clinic time, travel time, and parking time. Using real-time location system (RTLS) badge data, the researchers found that the median clinic time was 119 minutes, with a median total time (including travel and parking) of 197 minutes. The study highlights the significant time burdens imposed by cancer care, particularly for routine ambulatory appointments, which can take several hours. The findings suggest that many days with ambulatory health care contact may represent "lost days" for patients, emphasizing the need for improved care coordination and efficiency to reduce these time burdens. The study also notes that the time spent on ambulatory care is greater than that reported for the general adult population, likely due to the complexity and increased travel requirements of cancer care. The results support the inclusion of ambulatory contact days in overall health care contact days and provide baseline data for further care delivery reforms.This study quantifies the time patients with cancer spend on ambulatory appointments, including clinic time, travel time, and parking time. Using real-time location system (RTLS) badge data, the researchers found that the median clinic time was 119 minutes, with a median total time (including travel and parking) of 197 minutes. The study highlights the significant time burdens imposed by cancer care, particularly for routine ambulatory appointments, which can take several hours. The findings suggest that many days with ambulatory health care contact may represent "lost days" for patients, emphasizing the need for improved care coordination and efficiency to reduce these time burdens. The study also notes that the time spent on ambulatory care is greater than that reported for the general adult population, likely due to the complexity and increased travel requirements of cancer care. The results support the inclusion of ambulatory contact days in overall health care contact days and provide baseline data for further care delivery reforms.