When billing incident to, is there a time limitation for the treatment plan laid out by the collaborative physician in order to bill incident to? Fpr instance...if the patient was seen by the physician and told to follow up on their HTN in 6 months is there any problem billing this incident to? If the time frame is 1 year and the patient has been seen during that time for other problems but is following up on HTN a year later, can it still be billed incident to?