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ICD-10-CM 2027 diagnosis code

I25.85Chronic coronary microvascular dysfunction

✓ Billable / specific

I25.85 is a valid, billable ICD-10-CM code for chronic coronary microvascular dysfunction. 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 Coronary microvascular dysfunction.

Code last changed in FY2024 (effective October 1, 2023). Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About I25.85

I25.85 is the ICD-10-CM diagnosis code for chronic coronary microvascular dysfunction. It belongs to category I25 (chronic ischemic heart disease), block I20-I25 (ischemic heart diseases) 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 I25.8 (other forms of chronic ischemic heart disease), I25.85 is specifically for chronic coronary microvascular dysfunction. Related codes cover atherosclerosis of other coronary vessels without angina pectoris (I25.81), chronic total occlusion of coronary artery (I25.82), coronary atherosclerosis due to lipid rich plaque (I25.83), coronary atherosclerosis due to calcified coronary lesion (I25.84) and other forms of chronic ischemic heart disease (I25.89).

Use an additional code to identify: chronic total occlusion of coronary artery (I25.82), exposure to environmental tobacco smoke (Z77.22), history of tobacco dependence (Z87.891), occupational exposure to environmental tobacco smoke (Z57.31), tobacco dependence (F17.-) and 1 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 302 (Atherosclerosis with MCC, relative weight 1.1984) and DRG 303 (Atherosclerosis without MCC, relative weight 0.6612), in MDC 05 (Diseases and Disorders of the Circulatory System), 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 was added in FY2024, effective October 1, 2023.

Coding notes

Applicable toConditions and synonyms classified to this code
  • Chronic (presentation of) coronary microvascular disease
  • Coronary microvascular dysfunction NOS

Notes that apply from higher levels

Instructions written at a parent level also apply to I25.85.

› From I25 Chronic ischemic heart disease
Excludes2
  • non-ischemic myocardial injury (I5A)
Use additional code
  • code to identify:
  • chronic total occlusion of coronary artery (I25.82)
  • exposure to environmental tobacco smoke (Z77.22)
  • history of tobacco dependence (Z87.891)
  • occupational exposure to environmental tobacco smoke (Z57.31)
  • tobacco dependence (F17.-)
  • tobacco use (Z72.0)

Broader instructions also apply from I20-I25 Ischemic heart diseases and Chapter 9: Diseases of the circulatory system.

Alphabetic index entries

4 entries

Terms in the official ICD-10-CM index that lead to I25.85.

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 05 · Diseases and Disorders of the Circulatory System

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2024 (effective 10/1/2023): Added
  • No changes since FY2024.

Common questions about I25.85

Is I25.85 billable?

Yes. I25.85 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can I25.85 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict I25.85 as a principal diagnosis.

Is I25.85 a CC or MCC?

No. I25.85 is neither a CC nor an MCC under MS-DRG v44.0.

What DRG does I25.85 group to?

I25.85 is used in the MS-DRG v44.0 logic for MS-DRG 302 (Atherosclerosis with MCC) and MS-DRG 303 (Atherosclerosis without MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.