FY2021
Effective from
- Inherited rules changed
Episodic cluster headache
Category — select a more specific code
CDC/NCHS · FY2021headache NOS (R51.9)
For US diagnosis claims covered by HIPAA, ICD-10-CM is required from October 1, 2015.
Use the service date for outpatient/professional claims and the discharge date for hospital inpatient claims. Earlier encounters use ICD-9-CM; each individual code must also be valid for the applicable date.
Official coding guidelines → · CMS ↗First observed · 2015-10-01
Latest recorded change · FY2021
Effective from
Episodic cluster headache
Category — select a more specific code
CDC/NCHS · FY2021| All editions | Effective from | Code history |
|---|---|---|
| FY2016 | 2015-10-01 | First observed |
| FY2017 | 2016-10-01 | No tabular change |
| FY2018 | 2017-10-01 | No tabular change |
| FY2019 | 2018-10-01 | No tabular change |
| FY2020 | 2019-10-01 | No tabular change |
| FY2020 · April | 2020-04-01 | No tabular change |
| FY2021 | 2020-10-01 | Inherited rules changed |
| FY2021 · 01-01 | 2021-01-01 | No tabular change |
| FY2022 | 2021-10-01 | No tabular change |
| FY2022 · 04-01 | 2022-04-01 | No tabular change |
| FY2023 | 2022-10-01 | No tabular change |
| FY2023 · 04-01 | 2023-04-01 | No tabular change |
| FY2024 | 2023-10-01 | No tabular change |
| FY2024 · 04-01 | 2024-04-01 | No tabular change |
| FY2025 | 2024-10-01 | No tabular change |
| FY2025 · 04-01 | 2025-04-01 | No tabular change |
| FY2026 | 2025-10-01 | No tabular change |
| FY2026 · April | 2026-04-01 | No tabular change |
| FY2027 | 2026-10-01 | No tabular change |
The official Tabular List has no additional instructions at this code level.
Review the instructions inherited from its parent categories below. Inherited instructions ↓
headache NOS (R51.9)
Other entries in the same category; these are not automatic substitutes.
| Code | Description | Category · further specificity required |
|---|---|---|
| G44.00 | Cluster headache syndrome, unspecified | Category · further specificity required |
| G44.02 | Chronic cluster headache | Category · further specificity required |
| G44.03 | Episodic paroxysmal hemicrania | Category · further specificity required |
| G44.04 | Chronic paroxysmal hemicrania | Category · further specificity required |
| G44.05 | Short lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT) | Category · further specificity required |
| G44.09 | Other trigeminal autonomic cephalgias (TAC) | Category · further specificity required |
Official titles and instructions are preserved in their source language. Official sources ↗