I work in a busy little internal medicine practice and once in awhile my providers will bill and e/m code with a physical AND also smoking cessation. I know that I have to use a 25 mod on the E/M code, then I bill the physical with no modifier... but what do you do for smoking cessation code 99406? Does it even need a modifier? I tried using 59 on 99406 but that doesn't seem appropriate. Thank you for any help and guidance in advance!