Code 96372

Why is 99215 denied when billed with the same date of service as 96372? What s the reasoning behind it?

It's bundled

Office visit code 99215 and injection code 96372 are bundled normally. If submitted together, MCR will elect to pay for the E/M service vs the injection.
There are some exceptions where the E/M and the injection code, both performed on the same date, are actually significant and separate services, in which case you may bill them together with a modifier 25. Your documentation must support this, of course. (example: Pt scheduled OV for abdominal pain and expresses concern about recent flare of of psoriasis, so, it is determined that the patient will be given 10 mg of kenalog. You can bill for the E/M service, the injection and the drug with a modifier 25.)