2026 ICD-10-CM Diagnosis Code M46.88Other specified inflammatory spondylopathies, sacral and sacrococcygeal region

ICD-10-CM CodesM00–M99M45-M49M46

ICD-10-CM M46.88
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M46.88 is a billable ICD-10-CM diagnosis code for other specified inflammatory spondylopathies, sacral and sacrococcygeal region. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 551 through 552. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Spondylopathies/spondyloarthropathy (including infective).

M46.88 no longer risk-adjusts for Medicare Advantage: it mapped to HCC 40 under the retired CMS-HCC V24 model through payment year 2025 but maps to no category in the live V28 model. It still risk-adjusts in the PACE (CMS-HCC V22) category 40, ESRD (V21) category 40, and ESRD (V24) category 40 for payment year 2026.

Code Identity

ICD-10-CM Code
M46.88
Billable Status
Yes — Valid for Submission
Code Describes
Other specified inflammatory spondylopathies, sacral and sacrococcygeal region
Short Description
Oth inflammatory spondylopathies, sacr/sacrocygl region
Parent Code
Other specified inflammatory spondylopathies

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM45-M49Spondylopathies
CategoryM46Other inflammatory spondylopathies
This CodeM46.88Other specified inflammatory spondylopathies, sacral and sacrococcygeal region

Medicare Risk Adjustment (HCC)Billing

M46.88 no longer risk-adjusts for Medicare Advantage: it maps to no payment category in the live CMS-HCC V28 model, although it still risk-adjusts in the other CMS models shown below.

CMS-HCC V28 (Medicare Advantage Payment Model)
Not mapped
Dropped in V28 see all codes that no longer risk-adjust
Prior Model (CMS-HCC V24)
HCC 40
V24 retired last contributed to a Medicare Advantage risk score in payment year 2025
Other CMS Models
PACE (CMS-HCC V22): HCC 40 · ESRD (V21): HCC 40 · ESRD (V24): HCC 40
ESRD V21 weights: 0.072 dialysis, 0.274–0.398 functioning graft · ESRD V24 weights: 0.058 dialysis, 0.284–0.414 functioning graft
Part D (RxHCC)
Not mapped
M46.88 does not risk-adjust in the RxHCC prescription drug model

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.

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR MUS011
Spondylopathies/spondyloarthropathy (including infective)
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Spine Injuries and Disorders

Your backbone, or spine, is made up of 26 bone discs called vertebrae. The vertebrae protect your spinal cord and allow you to stand and bend. A number of problems can change the structure of the spine or damage the vertebrae and surrounding tissue. They include:

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert M46.88 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
720.89 Inflam spondylopathy NEC
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About M46.88Overview

Is M46.88 (Other specified inflammatory spondylopathies) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report other specified inflammatory spondylopathies, sacral and sacrococcygeal region on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does M46.88 group to?

When other specified inflammatory spondylopathies, sacral and sacrococcygeal region is the principal diagnosis on an inpatient stay, it groups to MS-DRG 551, 552, with relative weights from 0.9613 to 1.6761 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of M46.88?

Under the General Equivalence Mappings, other specified inflammatory spondylopathies, sacral and sacrococcygeal region converts to ICD-9-CM 720.89 (inflam spondylopathy NEC). The mapping is approximate, so confirm the match fits the documentation.

Does M46.88 risk-adjust for Medicare Advantage payment?

Not for Medicare Advantage. M46.88 mapped to HCC 40 in the retired CMS-HCC V24 model, which last determined payment in 2025, but it maps to no category in the live V28 model; see all codes that no longer risk-adjust. It still risk-adjusts in the PACE (CMS-HCC V22) category 40 (Rheumatoid Arthritis and Inflammatory Connective Tissue Disease), ESRD (V21) category 40 (Rheumatoid Arthritis and Inflammatory Connective Tissue Disease), and ESRD (V24) category 40 (Rheumatoid Arthritis and Inflammatory Connective Tissue Disease).