ICD-10-CM 2027 diagnosis code
I27.23Pulmonary hypertension due to lung diseases and hypoxia
I27.23 is a valid, billable ICD-10-CM code for pulmonary hypertension due to lung diseases and hypoxia. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.
Code last changed in FY2018 (effective October 1, 2017). Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data
About I27.23
I27.23 is the ICD-10-CM diagnosis code for pulmonary hypertension due to lung diseases and hypoxia. It belongs to category I27 (other pulmonary heart diseases), block I26-I28 (pulmonary heart disease and diseases of pulmonary circulation) 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 I27.2 (other secondary pulmonary hypertension), I27.23 is specifically for pulmonary hypertension due to lung diseases and hypoxia. Related codes cover pulmonary hypertension, unspecified (I27.20), secondary pulmonary arterial hypertension (I27.21), pulmonary hypertension due to left heart disease (I27.22), chronic thromboembolic pulmonary hypertension (I27.24) and other secondary pulmonary hypertension (I27.29).
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 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 was added in FY2018, effective October 1, 2017.
Before ICD-10, this condition was coded in ICD-9-CM as 416.8 (other chronic pulmonary heart diseases).
Coding notes
- Group 3 pulmonary hypertension
Notes that apply from higher levels
Instructions written at a parent level also apply to I27.23.
› From I27.2 Other secondary pulmonary hypertension
- Eisenmenger's syndrome (I27.83)
- associated underlying condition
Broader instructions also apply from Chapter 9: Diseases of the circulatory system.
Alphabetic index entries
2 entriesTerms in the official ICD-10-CM index that lead to I27.23.
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
ICD-9-CM equivalent
Converter →- 416.8Other chronic pulmonary heart diseasesapproximate
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
- FY2018 (effective 10/1/2017): Added
- No changes since FY2018.
Common questions about I27.23
Is I27.23 billable?
- Yes. I27.23 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can I27.23 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict I27.23 as a principal diagnosis.
Is I27.23 a CC or MCC?
- No. I27.23 is neither a CC nor an MCC under MS-DRG v44.0.
What DRG does I27.23 group to?
- I27.23 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 I27.23?
- The CMS General Equivalence Mappings map I27.23 to ICD-9-CM 416.8.