Multidrug resistant TB (MDR-TB) is triggered by a long treatment process and access to health facilities, potentially leading to TB treatment failure or lost to follow up. Various approaches in the treatment process have been carried out, but have not produced good results. To achieve the TB elimination target by 2030, new and innovative strategies are needed to identify TB, strengthen and expand laboratory-based surveillance, track initial loss to follow up (iLTFU) of MDR-TB patients, and develop TB vaccines. This study aims to design an application capable of tracking lost to follow up patients with a developed monitoring information system, which is expected to be able to send notifications for taking medication, visit schedules, patient tracking and TB-related education (SIMTb-Co application). The waterfall method was chosen to assess the use of SIMTb-Co (Comorbid Tb Monitoring Information System) application in several health centres in Medan City. The assessment of the use of the application has been started in June-August 2024 and it can be concluded that the SIMTb-Co application can be used in the service of pulmonary patients at Puskesmas and can show the treatment track record of pulmonary TB patients from the beginning of treatment until they are declared cured.