I apologize ahead of time for my ignorance, I am still new to coding/billing and have learned on the job through trial and error. I received 3 pages of denials from Medicare for " these are non-covered services because this is not deemed a "medical necessity" by the payer". But the codes used were 99203 (on 2 of patients), 99213 (on 8 patients) and 95972 (1 patient). All were billed with a minimum of 3 ICD-10 codes. I have checked the LCD rules and since 99213 and 99203 are office visits there aren't really any restrictions on what the diagnosis codes can be. I am at a loss as to what is incorrect on all of these.