The problem with this reasoning is that any f/u visit can be manipulated into a level 5, which is clearly inappropriate. The question, then, is for any given f/u visit, how much PE and HPI is medically necessary and appropriate.
theres the key. upcoding by doing unnecessary PE or HPI would be inappropriate. but if you have justification for doing so...
if you bill by MDM alone, but you do not document either a PE or HPI commisurate with the level of MDM, i think you would get dinged too. i do not believe a single component of level 3 is adequate enough documentation to bill a level 3 visit. it seems easier to document an appropriate PE or HPI with a higher level MDM, however.
as a side note, for a follow up on an injection, typically i:
-review the benefits, % and duration.
-review the potential side effects, including those related to steroids if used.
-review the purpose of the injection - not just for pain, but to allow patients to work aggressively on their primary long term therapeutic interventions - ie PT, CBT. i make sure necessary referrals are in place, or home exercise program has been initiated, and discuss how to advance or improve what is being done.
-check Vital signs, examine the site of the injection (skin), the targetted organ systems(generally, musculoskeletal and/or neurologic) (at least 2 organ systems).
-review the course of therapy - when to repeat injections, expected duration of benefits, when to contact the office to discuss the need for further injections, when to schedule routine follow ups.
with the exception of TPIs, imo that should qualify as a level 3.
(a level 2 follow up might be "so you went to PT? no better? go back...")