ICD-10-CM Codes
I00-I99 Diseases of the circulatory system
I60-I69 Cerebrovascular diseases
I66- Occlusion and stenosis of cerebral arteries, not resulting in cerebral infarction
2021 ICD-10-CM Diagnosis Code I66.21

2021 ICD-10-CM Diagnosis Code I66.21

Occlusion and stenosis of right posterior cerebral artery

2016

2017

2018

2019

2020

2021

Billable/Specific Code

I66.21 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
The 2021 edition of ICD-10-CM I66.21 became effective on October 1, 2020.
This is the American ICD-10-CM version of I66.21 - other international versions of ICD-10 I66.21 may differ.

The following code(s) above I66.21 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 I66.21:

I00-I99
2021 ICD-10-CM Range I00-I99
Diseases of the circulatory 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)
- systemic connective tissue disorders (M30-M36)
- transient cerebral ischemic attacks and related syndromes (G45.-)
Diseases of the circulatory system
I60-I69
2021 ICD-10-CM Range I60-I69
Cerebrovascular diseases
Type 1 Excludes
- traumatic intracranial hemorrhage (S06.-)
Use Additional
- code to identify presence of:
- alcohol abuse and dependence (F10.-)
- exposure to environmental tobacco smoke (Z77.22)
- history of tobacco dependence (Z87.891)
- hypertension (I10-I16)
- occupational exposure to environmental tobacco smoke (Z57.31)
- tobacco dependence (F17.-)
- tobacco use (Z72.0)
Cerebrovascular diseases
I66
ICD-10-CM Diagnosis Code I66
Occlusion and stenosis of cerebral arteries, not resulting in cerebral infarction
Includes
- embolism of cerebral artery
- narrowing of cerebral artery
- obstruction (complete) (partial) of cerebral artery
- thrombosis of cerebral artery
Type 1 Excludes
- Occlusion and stenosis of cerebral artery causing cerebral infarction (I63.3-I63.5)
Occlusion and stenosis of cerebral arteries, not resulting in cerebral infarction

Approximate Synonyms

Right posterior cerebral artery occlusion

ICD-10-CM I66.21 is grouped within Diagnostic Related Group(s) (MS-DRG v38.0):

061 Ischemic stroke, precerebral occlusion or transient ischemia with thrombolytic agent with mcc
062 Ischemic stroke, precerebral occlusion or transient ischemia with thrombolytic agent with cc
063 Ischemic stroke, precerebral occlusion or transient ischemia with thrombolytic agent without cc/mcc
067 Nonspecific cva and precerebral occlusion without infarction with mcc
068 Nonspecific cva and precerebral occlusion without infarction without mcc
791 Prematurity with major problems
793 Full term neonate with major problems

Convert I66.21 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

ICD-10-CM Codes Adjacent To I66.21

I66.01 Occlusion and stenosis of right middle cerebral artery

I66.02 Occlusion and stenosis of left middle cerebral artery

I66.03 Occlusion and stenosis of bilateral middle cerebral arteries

I66.09 Occlusion and stenosis of unspecified middle cerebral artery

I66.1 Occlusion and stenosis of anterior cerebral artery

I66.11 Occlusion and stenosis of right anterior cerebral artery

I66.12 Occlusion and stenosis of left anterior cerebral artery

I66.13 Occlusion and stenosis of bilateral anterior cerebral arteries

I66.19 Occlusion and stenosis of unspecified anterior cerebral artery

I66.2 Occlusion and stenosis of posterior cerebral artery

I66.21 Occlusion and stenosis of right posterior cerebral artery

I66.22 Occlusion and stenosis of left posterior cerebral artery

I66.23 Occlusion and stenosis of bilateral posterior cerebral arteries

I66.29 Occlusion and stenosis of unspecified posterior cerebral artery

I66.3 Occlusion and stenosis of cerebellar arteries

I66.8 Occlusion and stenosis of other cerebral arteries

I66.9 Occlusion and stenosis of unspecified cerebral artery

I67 Other cerebrovascular diseases

I67.0 Dissection of cerebral arteries, nonruptured

I67.1 Cerebral aneurysm, nonruptured

I67.2 Cerebral atherosclerosis

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

2021 ICD-10-CM Diagnosis Code I66.21

Occlusion and stenosis of right posterior cerebral artery

Diseases of the circulatory system

Cerebrovascular diseases

Occlusion and stenosis of cerebral arteries, not resulting in cerebral infarction