ICD-10-CM 2027
ICD-10 code for TAC NEC
From the official ICD-10-CM alphabetic index entry “TAC (trigeminal autonomic cephalgia) NEC”. Page updated September 29, 2026.
About coding TAC NEC
The ICD-10-CM code for TAC NEC is G44.099 (Other trigeminal autonomic cephalgias (TAC), not intractable). The official index lists 2 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on G44.099.
Within G44.09 (other trigeminal autonomic cephalgias (TAC)), G44.099 is specifically for other trigeminal autonomic cephalgias (TAC), not intractable. Related codes cover intractable (G44.091).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 102 (Headaches with MCC, relative weight 1.1201) and DRG 103 (Headaches without MCC, relative weight 0.822), in MDC 01 (Diseases and Disorders of the Nervous System), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
More specific TAC NEC codes (official index)
Common questions about TAC NEC ICD-10 codes
What is the ICD-10 code for TAC NEC?
- G44.099 — Other trigeminal autonomic cephalgias (TAC), not intractable. More specific codes apply when the documentation supports them: G44.091, G44.099.
What is the ICD-10 code for intractable tac nec?
- G44.091 — Other trigeminal autonomic cephalgias (TAC), intractable.
Is G44.099 billable?
- Yes. G44.099 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can G44.099 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict G44.099 as a principal diagnosis.
Is G44.099 a CC or MCC?
- No. G44.099 is neither a CC nor an MCC under MS-DRG v44.0.