G44.009 — Cluster headache syndrome, unspecified, not intractable
Is G44.009 billable?
Yes, but G44.009 is an unspecified code. G44.009 is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, G44.009 is an unspecified or catch-all code. Payers apply additional scrutiny to unspecified codes and many deny them when the medical record supports a more specific option, so check the documentation before selecting G44.009 — the more specific alternatives are listed below.
More specific alternatives
G44.009 at a glance
| Code | G44.009 |
|---|---|
| Description | Cluster headache syndrome, unspecified, not intractable |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
Which MS-DRGs does G44.009 group to?
G44.009 sits in MDC 01 and helps define the logic of 2 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.
- 102Headaches with MCCmedical
- 103Headaches without MCCmedical
How is G44.009 listed in the Alphabetic Index?
These are the routes through the Alphabetic Index that lead to G44.009. They show the wording a clinician may have documented, which often differs from the Tabular description.
- Cephalgia, cephalalgia › histamine
- Headache › cluster
- Headache › histamine
- Neuralgia, neuralgic › ciliary (acute)
- Neuralgia, neuralgic › migrainous (acute)
- Syndrome › cluster headache
- Cephalgia, cephalalgia › histamine › not intractable
- Headache › cluster › not intractable
- Headache › histamine › not intractable
- Neuralgia, neuralgic › ciliary › not intractable (acute)
- Neuralgia, neuralgic › migrainous › not intractable (acute)
- Syndrome › cluster headache › not intractable
Inclusion terms
Alternative wording in documentation that is classified to G44.009.
- Cluster headache syndrome NOS
Excludes1 — never code together — inherited from G44
The conditions below can never be reported together with G44.009 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
- headache NOS (R51.9)
Excludes2 — not included here — inherited from Chapter 6
The conditions below are not part of G44.009, but a patient may have both at the same time. When documentation supports it, G44.009 and the excluded code may both be reported.
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
Excludes2 — not included here — inherited from G44
The conditions below are not part of G44.009, but a patient may have both at the same time. When documentation supports it, G44.009 and the excluded code may both be reported.
How long has G44.009 existed?
G44.009 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.