2026 ICD-10-CM Diagnosis Code I09.81Rheumatic heart failure
ICD-10-CM Codes›I00–I99›I05-I09›I09
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- Risk Adjusts — HCC 226
- Chronic Condition
I09.81 is a billable ICD-10-CM diagnosis code for rheumatic heart failure. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 291 through 293, 791, 793. 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 33 closely related codes. Coders also document this condition as chronic congestive heart failure. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Chronic rheumatic heart disease and Heart failure.
For Medicare Advantage risk adjustment, I09.81 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 heart failure.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
I09.81 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.
- Chronic congestive heart failure
- Chronic left-sided congestive heart failure
- Chronic left-sided heart failure
- Congestive rheumatic heart failure
- Rheumatic left ventricular failure
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Use Additional Code
- code to identify type of heart failure I50
The “use additional code” indicates that a secondary code could be used to further specify the patient’s condition. This note is not mandatory and is only used if enough information is available to assign an additional code.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
ventricular See Also: Failure, heart; I50.9
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
Heart Failure
Heart failure means that your heart can't pump enough oxygen-rich blood to meet your body's needs. Heart failure doesn't mean that your heart has stopped or is about to stop beating. But without enough blood flow, your organs may not work well, which can cause serious problems.
The full article covers:
- What is heart failure?
- What causes heart failure?
- Who is more likely to develop heart failure?
- What are the symptoms of heart failure?
- What other problems does heart failure cause?
- How is heart failure diagnosed?
- What are the treatments for heart failure?
- Can heart failure be prevented?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert I09.81 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About I09.81Overview
What is the ICD-10 code for rheumatic heart failure?
The ICD-10-CM code for rheumatic heart failure is I09.81 (sometimes written as I0981). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
Is I09.81 (Other specified rheumatic heart diseases) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report rheumatic heart failure on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does I09.81 group to?
When rheumatic heart failure is the principal diagnosis on an inpatient stay, it groups to MS-DRG 291, 292, 293, 791, 793, with relative weights from 0.5660 to 4.1696 depending on complications. Higher weights mean higher Medicare reimbursement.
Is I09.81 a CC or MCC?
CMS lists I09.81 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 33 closely related codes in its exclusion list.
What is the ICD-9 equivalent of I09.81?
Under the General Equivalence Mappings, rheumatic heart failure converts to ICD-9-CM 398.91 (rheumatic heart failure). The mapping is a direct match.
What HCC is I09.81?
I09.81 (rheumatic heart failure) 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 186.
Does I09.81 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, I09.81 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.
