Question: How do we code for brainstem auditory evoked response (BAER) testing? New Jersey Subscriber Answer: You will find BAER in CPT 2009's -Audiologic Function Tests- section rather than in the -Evoked Potentials and Reflex Tests- section, which includes the balance of the other evoked potential diagnostic study CPT codes. The correct codes are 92585 (Auditory evoked potentials for evoked response audiometry and/or testing of the central nervous system;comprehensive) or 95286 (... limited). Take note: BAER services include testing for both ears. Use modifier 52 (Reduced services) if your neurologist tests only one ear.