Described are systems and methods for compensating long term sensitivity drift of catalytic type electrochemical gas sensors used in systems for delivering therapeutic nitric oxide (NO) gas to a patient by compensating for drift that may be specific to the sensors atypical use in systems for delivering therapeutic nitric oxide gas to a patient. In at least some instances, the long term sensitivity drift of catalytic type electrochemical gas sensors can be addressed using calibration schedules, which can factor in the absolute change in set dose of NO being delivered to the patient that can drive one or more baseline calibrations. The calibration schedules can be used reduce the amount of times the sensor goes offline. Systems and methods described may factor in actions occurring at the delivery system and/or aspects of the surrounding environment, prior to performing a baseline calibration, and may postpone the calibration and/or rejected using the sensor's output for the calibration.