Regarding question #1- Constant Attendance require the provider to be with the patient at all times. Modalities requiring constant attendance of the provider require direct one on one patient contact by the provider and are also time-based. (97150 requires the provider to have direct contact with the group.) Providers can bill multiple units of these codes per discipline, per beneficiary, on the same day of treatment. Constant attendance doesn't just mean the provider needs to be in the room, it is used to describe modalities requiring the constant intervention and clinical decision making of the therapist, or problem solving ability of the assistant, to achieve the desired result. (examples of doing an ultrasound, manual therapy) 

 

Regarding question #2- Yes, 97150 is an untimed code. Group procedures involve constant attendance of the therapist but do not require one on one patient contact by the therapist, and they are untimed. Providers may only bill one unit of group therapy per discipline, per beneficiary, per day, making this an untimed code. Other examples of an untimed codes are 97010, 97014. Therefore if you work with 2 pts in one hour, you can bill a group charge. That is one unit of 97150 for pt A and one unit of 97150 for pt B. But if you spending direct one on one with each patient doing ther. ex.(even going between them but working individually with each working on goals) then you may bill 2 units of 97110 for pt A and 2 units of 97110 for pt B.