I28.9 Disease of pulmonary vessels, unspecified
The ICD-10-CM code for Disease of pulmonary vessels, unspecified is I28.9 (FY2026). It is a billable, claim-ready diagnosis code.
Classification
- Section
- I26-I28: Pulmonary heart disease and diseases of pulmonary circulation (I26-I28)
- Category I28
- 5 codes (4 billable)
- FY2026 Status
- Stable since FY2024
Also Known As
ICD-10-CM Alphabetic Index entries that lead to I28.9:
- Disease, diseased › pulmonary › artery
U.S. Hospital Utilization
- An estimated 280 U.S. inpatient stays in 2023 included I28.9 among the documented diagnoses.
Source: National Inpatient Sample (NIS), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality, 2016–2023. National survey-weighted estimates.
Official Coding Guidelines
Presumed relationship due to Index term “with”The classification presumes a causal relationship between hypertension and heart involvement and between hypertension and kidney involvement, as the two conditions are linked by the term “with” in the Alphabetic Index. These conditions should be coded as related even in the absence of provider documentation explicitly linking them, unless the documentation clearly states the conditions are unrelated.
Provider must link conditions not specifically indexed as relatedFor hypertension and conditions not specifically linked by relational terms such as “with,” “associated with” or “due to” in the classification, provider documentation must link the conditions in order to code them as related.
Source: CMS — ICD-10-CM Official Guidelines for Coding and Reporting, FY2026