G44.099 — Other trigeminal autonomic cephalgias (TAC), not intractable
G44.099 is a billable, specific ICD-10-CM code for other trigeminal autonomic cephalgias (tac), not intractable. It is valid for submission on a claim.
Risk adjustment
G44.099 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.
Medicare coverage
G44.099 is named in 2 Medicare coverage policies — 2 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.
- A56612Billing and Coding: CT of the Head
- A57204Billing and Coding: MRI and CT Scans of the Head and Neck
How G44.099 is indexed
Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to G44.099.
- Horton's headache or neuralgia
- TAC NEC(trigeminal autonomic cephalgia)
- Cephalgia, cephalalgia›trigeminal autonomic NEC(TAC)
- Horton's headache or neuralgia›not intractable
- Neuralgia, neuralgic›Horton's
- TAC NEC›not intractable
- Cephalgia, cephalalgia›trigeminal autonomic NEC›not intractable
- Neuralgia, neuralgic›Horton's›not intractable
Related codes at this level
Codes that share G44.09. If G44.099 is not quite right, the correct code is usually one of these.
Questions about G44.099
- Is G44.099 a billable ICD-10-CM code?
- Yes. G44.099 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
- Where does G44.099 sit in the tabular list?
- Diseases of the nervous system (G00-G99), in the block Episodic and paroxysmal disorders (G40-G47).