ICD-10-CM 2027
ICD-10 code for thunderclap primary headache
From the official ICD-10-CM alphabetic index entry “Headache › thunderclap (primary)”. Page updated September 29, 2026.
About coding thunderclap primary headache
The ICD-10-CM code for thunderclap primary headache is G44.53 (Primary thunderclap headache).
Within G44.5 (complicated headache syndromes), G44.53 is specifically for primary thunderclap headache. Related codes cover hemicrania continua (G44.51), New daily persistent headache (NDPH) (G44.52) and other complicated headache syndrome (G44.59).
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.
Common questions about thunderclap primary headache ICD-10 codes
What is the ICD-10 code for thunderclap primary headache?
- G44.53 — Primary thunderclap headache.
Is G44.53 billable?
- Yes. G44.53 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can G44.53 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict G44.53 as a principal diagnosis.
Is G44.53 a CC or MCC?
- No. G44.53 is neither a CC nor an MCC under MS-DRG v44.0.