Hospital outpatient waiting times in Indonesia do not meet the standards. Lean management reduces waste, while digitalization plays a role in managing service complexity. Implementing lean in parallel with digitalization increases the opportunities for improvements, but empirical research on this is still limited. This study aimed to generate an analytical study of the impact of Lean application in reducing the waste of waiting time for outpatient services at a government hospital. The research design was pre-and post-intervention. The study was conducted in a regional government hospital with 80 people as a sample who was recruited by systematic random sampling. Data collection was carried out through observation and mapping the flow of patient service time from booking to completion of a doctor's consultation using the time stamp. Efforts to reduce waiting time are carried out through a simulation of the Lean-based digitalization model. The variables are the number of Service Steps, Lead Time, Waiting Time, Value-Added Activities, Non-Value-Added Activities and Value-Added Ratio (VAR). The results showed that lean-based service digitalization was able to reduce service steps from 10 to 4 steps, waste waiting from 5 to 2 steps, and Lead Time from 336 to 39 minutes (-88.4%), increasing the VAR from 5.1% to 20.5%. This research is limited to the implementation of lean digitally. It is important to statistically compare the impact of digital and non-digital lean implementation in some hospitals.