The 92xxx codes require that treatment or diagnostic testing is begun or continued for the patient. There are lots of different opinions as to what constitutes treatments. Some believe that treatment only occurs when a prescription is written for a medication to be taken by the patient.
Personally, I believe that's overly restrictive. As an example, for a patient with dry eye or mild ocular allergies, OTC drops or other palliative methods may be recommended. To me, that constitutes treatment. If you have a patient who has glaucoma and you check them periodically to be sure their glaucoma drops are working properly and you don't change their medication, that's continued treatment.
From my standpoint, as long as the Hx, Exam and MDM elements are met for a new patient exam, I recommend billing the 99202-04 codes. For any established patient who meets the treatment or diagnostic testing criteria should have their visit billed using the 9201x codes. Doing this, maximizes income for the level of service given to the patients.
The codes you use aren't diagnosis specific in most cases. However, certain carriers will try to restrict which code set you use, usually to the carrier's financial benefit. If they do that, I recommend that my clients appeal those restrictions because both code sets are valid for use when providing eye care services.
Tom Cheezum, OD, CPC, COPC