When billing this code for a transients patient either on vacation or is moving and has had 3 treatments at our center, and the rest of that month at another center.

What is the proper way to bill this code with a from and to date of service and indicated the numbers of units? Do you always bill 90970, even if you provider, did provider a Complete Assessment? Do you ever need to provide an admit and discharge date I’m being told you do, but this is outpatient services. I usually bill a from and to date of service, and the number of units. How do you handle a situation where the patient was in you care for part of the month physician provides Complete Assessment, patient has 2 more visits and moves onto new center to complete treatment. If we bill the code as 90961, most time it is denied because another provider has already billed those services, what is the option here????