2026 ICD-10-CM Diagnosis Code I27.0Primary pulmonary hypertension
ICD-10-CM Codes›I00–I99›I26-I28›I27
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- Risk Adjusts — HCC 226
- Chronic Condition
I27.0 is a billable ICD-10-CM diagnosis code for primary pulmonary hypertension. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 314 through 316. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 21 closely related codes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Pulmonary heart disease.
For Medicare Advantage risk adjustment, I27.0 maps to CMS-HCC Category 226 (Heart Failure, Except End Stage and Acute) under the V28 model, adding a risk factor of about 0.360 for a community, non-dual, aged beneficiary in payment year 2026.
This medical diagnosis code is frequently used in Cardiology medical specialties to designate conditions such hypertension.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
I27.0 maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2026.
Source: CMS Payment Year 2026 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Ayerza's syndrome
- Cor pulmonale
- Familial primary pulmonary hypertension
- Finding of pulmonary arterial pressure
- Heritable pulmonary arterial hypertension
- Heritable pulmonary arterial hypertension due to ALK1 or endoglin mutation
- Heritable pulmonary arterial hypertension due to BMPR2 mutation
- Idiopathic pulmonary arterial hypertension
- Idiopathic pulmonary arteriosclerosis
- Pulmonary arterial pressure above reference range
- Right ventricular failure due to pulmonary vascular disease
- Sporadic primary pulmonary hypertension
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Inclusion Terms
- Heritable pulmonary arterial hypertension
- Idiopathic pulmonary arterial hypertension
- Primary group 1 pulmonary hypertension
- Primary pulmonary arterial hypertension
Type 1 Excludes
- persistent pulmonary hypertension of newborn P29.30
- pulmonary hypertension NOS I27.20
- secondary pulmonary arterial hypertension I27.21
- secondary pulmonary hypertension I27.29
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Arteriosclerosis, arteriosclerotic (diffuse) (obliterans) (of) (senile) (with calcification) I70.90
pulmonary (idiopathic) I27.0
Cardiopathia nigra I27.0
Disease, diseased See Also: Syndrome;
Ayerza's (pulmonary artery sclerosis with pulmonary hypertension) I27.0
black I27.0
pulmonary See Also: Disease, lung;
hypertensive (vascular) See Also: Hypertension, pulmonary; I27.20
primary (idiopathic) I27.0
Hypertension, hypertensive (accelerated) (benign) (essential) (idiopathic) (malignant) (systemic) I10
lesser circulation I27.0
primary (idiopathic) I27.0
Syndrome See Also: Disease;
Arrillaga-Ayerza I27.0
Ayerza (-Arrillaga) I27.0
cardiacos negros I27.0
arteriosclerosis I27.0
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Familial Primary Pulmonary Hypertension
familial or idiopathic hypertension in the pulmonary circulation which is not secondary to other disease.Pulmonary Circulation
the circulation of the blood through the lungs.
Patient EducationClinical
Pulmonary Hypertension
Pulmonary hypertension, sometimes called PH, is a serious condition that affects the blood vessels in the lungs. It develops when the blood pressure in your lungs is higher than normal.
The full article covers:
- What is pulmonary hypertension?
- What causes pulmonary hypertension?
- Who is more likely to develop pulmonary hypertension?
- What are the symptoms of pulmonary hypertension?
- What other problems can pulmonary hypertension cause?
- How is pulmonary hypertension diagnosed?
- What are the treatments for pulmonary hypertension?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert I27.0 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About I27.0Overview
What is the ICD-10 code for primary pulmonary hypertension?
The ICD-10-CM code for primary pulmonary hypertension is I27.0 (sometimes written as I270). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
Is I27.0 (Other pulmonary heart diseases) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report primary pulmonary hypertension on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does I27.0 group to?
When primary pulmonary hypertension is the principal diagnosis on an inpatient stay, it groups to MS-DRG 314, 315, 316, with relative weights from 0.6821 to 2.0852 depending on complications. Higher weights mean higher Medicare reimbursement.
Is I27.0 a CC or MCC?
CMS lists I27.0 as a CC (complication or comorbidity) for FY 2026. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 21 closely related codes in its exclusion list.
What is the ICD-9 equivalent of I27.0?
Under the General Equivalence Mappings, primary pulmonary hypertension converts to ICD-9-CM 416.0 (prim pulm hypertension). The mapping is a direct match.
What HCC is I27.0?
I27.0 (primary pulmonary hypertension) maps to CMS-HCC Category 226 (Heart Failure, Except End Stage and Acute), commonly written as HCC 226, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2026. It mapped to HCC 85 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. In the Part D prescription drug model it maps to RxHCC 183.
Does I27.0 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, I27.0 adds a risk adjustment factor of about 0.360 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.217 to 0.537 depending on the payment segment). A more severe related category (HCC 221, HCC 222, HCC 223, HCC 224, and HCC 225) supersedes it when both are reported. See the full factor table on the HCC 226 category page.
