An add-on code may only be billed alongside an acceptable primary procedure. Enter either side — the add-on to see what it may accompany, or a primary to see which add-ons it supports.
Same visit, same extra 20 minutes — and the add-on code depends entirely on who is paying.
A level-5 office visit (99205 or 99215) runs long. The prolonged time is billable — but there is no universal code for it. Commercial and Medicare disagreed on the math, so each recognizes a different add-on and denies the other.
AMA · CPT
The AMA add-on for prolonged time on a high-level office visit. Commercial payers that follow CPT accept it on a qualifying primary such as 99205 or 99215.
On a Medicare claim it denies — CMS assigns it status I (invalid) and does not recognize it.
CMS · HCPCS
CMS rejected the AMA's time thresholds and built its own add-on. Medicare requires G2212 for the same prolonged time, and accepts it only against the short list of primaries it publishes — the level-5 office visits among them.
On a commercial claim it usually denies — most non-Medicare payers do not recognize the G-code.
The engineering takeaway:an add-on rule is not universal. The same claim is correct or denied depending on the payer, so the edit logic has to branch on payer before it decides the code — +99417 for commercial, G2212 for Medicare, each denied on the other. Which primaries each one may attach to is a separate question, and the answer changes by quarter — so look it up rather than memorise it.
Look up either code to see the primaries it may be billed with. Try or .