2026 ICD-10-CM Diagnosis Code M86.471Chronic osteomyelitis with draining sinus, right ankle and foot
ICD-10-CM Codes›M00–M99›M86-M90›M86
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- Risk Adjusts — HCC 92
- Not Chronic
M86.471 is a billable ICD-10-CM diagnosis code for chronic osteomyelitis with draining sinus, right ankle and foot. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 539 through 541. 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 205 closely related codes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Osteomyelitis.
For Medicare Advantage risk adjustment, M86.471 maps to CMS-HCC Category 92 (Bone/Joint/Muscle/Severe Soft Tissue Infections/Necrosis) under the V28 model, adding a risk factor of about 0.479 for a community, non-dual, aged beneficiary in payment year 2026.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
M86.471 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.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
Bone Infections
Like other parts of the body, bones can get infected. The infections are usually bacterial, but can also be fungal. They may spread to the bone from nearby skin or muscles, or from another part of the body through the bloodstream.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert M86.471 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About M86.471Overview
What is the ICD-10 code for chronic osteomyelitis with draining sinus, right ankle and foot?
The ICD-10-CM code for chronic osteomyelitis with draining sinus, right ankle and foot is M86.471 (sometimes written as M86471). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
Is M86.471 (Chronic osteomyelitis with draining sinus, ankle and foot) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report chronic osteomyelitis with draining sinus, right ankle and foot on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does M86.471 group to?
When chronic osteomyelitis with draining sinus, right ankle and foot is the principal diagnosis on an inpatient stay, it groups to MS-DRG 539, 540, 541, with relative weights from 0.7715 to 1.9697 depending on complications. Higher weights mean higher Medicare reimbursement.
Is M86.471 a CC or MCC?
CMS lists M86.471 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 205 closely related codes in its exclusion list.
What is the ICD-9 equivalent of M86.471?
Under the General Equivalence Mappings, chronic osteomyelitis with draining sinus, right ankle and foot converts to ICD-9-CM 730.17 (chr osteomyelit-ankle). The mapping is approximate, so confirm the match fits the documentation.
What HCC is M86.471?
M86.471 (chronic osteomyelitis with draining sinus, right ankle and foot) maps to CMS-HCC Category 92 (Bone/Joint/Muscle/Severe Soft Tissue Infections/Necrosis), commonly written as HCC 92, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2026. It mapped to HCC 39 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. It does not map to any RxHCC in the Part D prescription drug model.
Does M86.471 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, M86.471 adds a risk adjustment factor of about 0.479 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.471 to 0.632 depending on the payment segment). HCC 92 sits at the top of its hierarchy, so no other condition category supersedes it. See the full factor table on the HCC 92 category page.
