While 99453 is for the initial setup, CPT 99454 is the code you bill every month for supplying the Remote Patient Monitoring (RPM) device and transmitting the data.
Billing Requirements for 99454
99454 is billed once per 30-day period. The device must meet the FDA definition of a medical device, and it must automatically digitally transmit the data (patients cannot manually text or email you their blood pressure numbers).
The 16-Day Rule (Medical Necessity)
Just like the setup code, you can only bill 99454 if the patient has transmitted data on at least 16 different days during the 30-day billing cycle. If they only transmit on 15 days, you lose the entire month's reimbursement.
Multiple Devices
If the patient has a blood pressure cuff and a weight scale, you only bill 99454 once. It is billed per patient, not per device.