ICD-10-CM Codes
G00-G99
G40-G47
G44-
2023 ICD-10-CM Diagnosis Code G44.021

2023 ICD-10-CM Diagnosis Code G44.021

Chronic cluster headache, intractable

2016

2017

2018

2019

2020

2021

2022

2023

Billable/Specific Code

G44.021 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
The 2023 edition of ICD-10-CM G44.021 became effective on October 1, 2022.
This is the American ICD-10-CM version of G44.021 - other international versions of ICD-10 G44.021 may differ.

The following code(s) above G44.021 contain annotation back-references

Annotation Back-References

In this context, annotation back-references refer to codes that contain:

Applicable To annotations, or
Code Also annotations, or
Code First annotations, or
Excludes1 annotations, or
Excludes2 annotations, or
Includes annotations, or
Note annotations, or
Use Additional annotations

that may be applicable to G44.021:

G00-G99
2023 ICD-10-CM Range G00-G99
Diseases of the nervous system
Type 2 Excludes
- 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)
Diseases of the nervous system
G44
ICD-10-CM Diagnosis Code G44
Other headache syndromes
Type 1 Excludes
- headache NOS (R51.9)
Type 2 Excludes
- atypical facial pain (G50.1)
- headache due to lumbar puncture (G97.1)
- migraines (G43.-)
- trigeminal neuralgia (G50.0)
Other headache syndromes

Approximate Synonyms

Chronic intractable cluster headache
Cluster headache, chronic intractable

ICD-10-CM G44.021 is grouped within Diagnostic Related Group(s) (MS-DRG v40.0):

102 Headaches with mcc
103 Headaches without mcc

Convert G44.021 to ICD-9-CM

Code History

2016 (effective 10/1/2015): New code (first year of non-draft ICD-10-CM)
2017 (effective 10/1/2016): No change
2018 (effective 10/1/2017): No change
2019 (effective 10/1/2018): No change
2020 (effective 10/1/2019): No change
2021 (effective 10/1/2020): No change
2022 (effective 10/1/2021): No change
2023 (effective 10/1/2022): No change

Diagnosis Index entries containing back-references to G44.021:

Headache R51.9
ICD-10-CM Diagnosis Code R51.9
Headache, unspecified
Applicable To
Facial pain NOS
- cluster G44.009
  ICD-10-CM Diagnosis Code G44.009
  Cluster headache syndrome, unspecified, not intractable
  2016 2017 2018 2019 2020 2021 2022 2023 Billable/Specific Code
  Applicable To
  Cluster headache syndrome NOS
  - chronic G44.029
    ICD-10-CM Diagnosis Code G44.029
    Chronic cluster headache, not intractable
    2016 2017 2018 2019 2020 2021 2022 2023 Billable/Specific Code
    Applicable To
    Chronic cluster headache NOS
    - intractable G44.021

ICD-10-CM Codes Adjacent To G44.021

G43.919 …… without status migrainosus

G44 Other headache syndromes

G44.0 Cluster headaches and other trigeminal autonomic cephalgias (TAC)

G44.00 Cluster headache syndrome, unspecified

G44.001 …… intractable

G44.009 …… not intractable

G44.01 Episodic cluster headache

G44.011 …… intractable

G44.019 …… not intractable

G44.02 Chronic cluster headache

G44.021 …… intractable

G44.029 …… not intractable

G44.03 Episodic paroxysmal hemicrania

G44.031 …… intractable

G44.039 …… not intractable

G44.04 Chronic paroxysmal hemicrania

G44.041 …… intractable

G44.049 …… not intractable

G44.05 Short lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT)

G44.051 …… intractable

G44.059 …… not intractable

Reimbursement claims with a date of service on or after October 1, 2015 require the use of ICD-10-CM codes.

2023 ICD-10-CM Diagnosis Code G44.021

Chronic cluster headache, intractable

Diseases of the nervous system

Other headache syndromes

Headache, unspecified

Cluster headache syndrome, unspecified, not intractable

Chronic cluster headache, not intractable