ICD-10-CM 2027 diagnosis code
I77.6Arteritis, unspecified
I77.6 is a valid, billable ICD-10-CM code for arteritis, unspecified. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.
Looking up by condition? See ICD-10 code for Angiitis, ICD-10 code for Aortitis, ICD-10 code for Arteritis, ICD-10 code for Vasculitis.
Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data
About I77.6
I77.6 is the ICD-10-CM diagnosis code for arteritis, unspecified. It belongs to category I77 (other disorders of arteries and arterioles), block I70-I79 (diseases of arteries, arterioles and capillaries) and chapter 9 (diseases of the circulatory system). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.
Within I77, choose I77.6 (Arteritis, unspecified) only when documentation doesn't support a more specific option: arteriovenous fistula, acquired (I77.0), stricture of artery (I77.1), rupture of artery (I77.2), arterial fibromuscular dysplasia (I77.3), celiac artery compression syndrome (I77.4), necrosis of artery (I77.5), other arterial dissection (I77.7), other specified disorders of arteries and arterioles (I77.8) and 1 more.
Don't report I77.6 together with the conditions in its Excludes1 note: aortic arch (M31.4), cerebral NEC (I67.7), coronary (I25.89), deformans (I70.-) and 3 more.
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 545 (Connective Tissue Disorders with MCC, relative weight 2.3892), DRG 546 (Connective Tissue Disorders with CC, relative weight 1.1745) and DRG 547 (Connective Tissue Disorders without CC/MCC, relative weight 0.7526), in MDC 08 (Diseases and Disorders of the Musculoskeletal System and Connective Tissue), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.
Before ICD-10, this condition was coded in ICD-9-CM as 447.6 (arteritis, unspecified).
Coding notes
- Aortitis NOS
- Endarteritis NOS
Notes that apply from higher levels
Instructions written at a parent level also apply to I77.6.
Broader instructions also apply from Chapter 9: Diseases of the circulatory system.
Alphabetic index entries
8 entriesTerms in the official ICD-10-CM index that lead to I77.6.
MS-DRG v44.0 grouping
All DRGs →Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.
MDC 08 · Diseases and Disorders of the Musculoskeletal System and Connective Tissue
ICD-9-CM equivalent
Converter →- 447.6Arteritis, unspecifiedexact
From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
- No changes since FY2016.
Common questions about I77.6
Is I77.6 billable?
- Yes. I77.6 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can I77.6 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict I77.6 as a principal diagnosis.
Is I77.6 a CC or MCC?
- No. I77.6 is neither a CC nor an MCC under MS-DRG v44.0.
What DRG does I77.6 group to?
- I77.6 is used in the MS-DRG v44.0 logic for MS-DRG 545 (Connective Tissue Disorders with MCC), MS-DRG 546 (Connective Tissue Disorders with CC) and MS-DRG 547 (Connective Tissue Disorders without CC/MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.
What is the ICD-9 code for I77.6?
- The CMS General Equivalence Mappings map I77.6 to ICD-9-CM 447.6.