ICD-10-CM 2027 diagnosis code
I27.0Primary pulmonary hypertension
I27.0 is a valid, billable ICD-10-CM code for primary pulmonary hypertension. 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 Cardiopathia nigra, ICD-10 code for Arrillaga-Ayerza syndrome, ICD-10 code for Ayerza's disease or syndrome.
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 I27.0
I27.0 is the ICD-10-CM diagnosis code for primary pulmonary hypertension. 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 (other pulmonary heart diseases), I27.0 is specifically for primary pulmonary hypertension. Related codes cover Kyphoscoliotic heart disease (I27.1), other secondary pulmonary hypertension (I27.2), other specified pulmonary heart diseases (I27.8) and pulmonary heart disease, unspecified (I27.9).
Don't report I27.0 together with the conditions in its Excludes1 note: persistent pulmonary hypertension of newborn (P29.30), pulmonary hypertension NOS (I27.20), secondary pulmonary arterial hypertension (I27.21) and secondary pulmonary hypertension (I27.29).
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 416.0 (primary pulmonary hypertension).
Coding notes
- Heritable pulmonary arterial hypertension
- Idiopathic pulmonary arterial hypertension
- Primary group 1 pulmonary hypertension
- Primary pulmonary arterial hypertension
Notes that apply from higher levels
Instructions written at a parent level also apply to I27.0.
Broader instructions also apply from Chapter 9: Diseases of the circulatory system.
Alphabetic index entries
14 entriesTerms in the official ICD-10-CM index that lead to I27.0.
- Arrillaga-Ayerza syndrome (pulmonary sclerosis with pulmonary hypertension)
- Arteriosclerosis, arteriosclerotic (diffuse) (obliterans) (of) (senile) (with calcification) › pulmonary (idiopathic)
- Ayerza's disease or syndrome (pulmonary artery sclerosis with pulmonary hypertension)
- Cardiopathia nigra
- Disease, diseased › Ayerza's (pulmonary artery sclerosis with pulmonary hypertension)
- Disease, diseased › heart (organic) › black
- Disease, diseased › pulmonary › hypertensive (vascular) › primary (idiopathic)
- Hypertension, hypertensive (accelerated) (benign) (essential) (idiopathic) (malignant) (systemic) › lesser circulation
- Hypertension, hypertensive (accelerated) (benign) (essential) (idiopathic) (malignant) (systemic) › pulmonary › primary (idiopathic)
- Sclerosis, sclerotic › pulmonary › artery
- Syndrome › Arrillaga-Ayerza
- Syndrome › Ayerza (-Arrillaga)
- Syndrome › cardiacos negros
- Syndrome › pulmonary › arteriosclerosis
Codes whose notes reference I27.0
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.
MDC 05 · Diseases and Disorders of the Circulatory System
ICD-9-CM equivalent
Converter →- 416.0Primary pulmonary hypertensionexact
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 I27.0
Is I27.0 billable?
- Yes. I27.0 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can I27.0 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict I27.0 as a principal diagnosis.
Is I27.0 a CC or MCC?
- I27.0 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.
What DRG does I27.0 group to?
- I27.0 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 I27.0?
- The CMS General Equivalence Mappings map I27.0 to ICD-9-CM 416.0.