Skip to content
Dx

ICD-10-CM 2027 diagnosis code

I31.0Chronic adhesive pericarditis

✓ Billable / specificCC — complication/comorbidity

I31.0 is a valid, billable ICD-10-CM code for chronic adhesive pericarditis. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.

Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS, effective October 1, 2026. Updated September 29, 2026. About our data

About I31.0

I31.0 is the ICD-10-CM diagnosis code for chronic adhesive pericarditis. It belongs to category I31 (other diseases of pericardium), block I30-I5A (other forms of heart disease) 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 I31 (other diseases of pericardium), I31.0 is specifically for chronic adhesive pericarditis. Related codes cover chronic constrictive pericarditis (I31.1), hemopericardium, not elsewhere classified (I31.2), pericardial effusion (noninflammatory) (I31.3), cardiac tamponade (I31.4), other specified diseases of pericardium (I31.8) and disease of pericardium, unspecified (I31.9).

As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.

In MS-DRG v44.0, it is part of the grouping logic for DRG 314 (Other Circulatory System Diagnoses with MCC, relative weight 2.0873), DRG 315 (Other Circulatory System Diagnoses with CC, relative weight 0.9508) and DRG 316 (Other Circulatory System Diagnoses without CC/MCC, relative weight 0.6677), 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 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 423.1 (adhesive pericarditis).

Coding notes

Applicable toConditions and synonyms classified to this code
  • Accretio cordis
  • Adherent pericardium
  • Adhesive mediastinopericarditis

Notes that apply from higher levels

Instructions written at a parent level also apply to I31.0.

› From I31 Other diseases of pericardium
Excludes1
  • diseases of pericardium specified as rheumatic (I09.2)
  • postcardiotomy syndrome (I97.0)
  • traumatic injury to pericardium (S26.-)

Broader instructions also apply from Chapter 9: Diseases of the circulatory system.

Alphabetic index entries

14 entries

Terms in the official ICD-10-CM index that lead to I31.0.

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.

ICD-9-CM equivalent

Converter →
  • 423.1Adhesive pericarditisexact

From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.

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
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about I31.0

Is I31.0 billable?

Yes. I31.0 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can I31.0 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict I31.0 as a principal diagnosis.

Is I31.0 a CC or MCC?

I31.0 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.

What DRG does I31.0 group to?

I31.0 is used in the MS-DRG v44.0 logic for MS-DRG 314 (Other Circulatory System Diagnoses with MCC), MS-DRG 315 (Other Circulatory System Diagnoses with CC) and MS-DRG 316 (Other Circulatory System Diagnoses 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 I31.0?

The CMS General Equivalence Mappings map I31.0 to ICD-9-CM 423.1.