2026 ICD-10-CM Diagnosis Code M02.30Reiter's disease, unspecified site

ICD-10-CM Codes›M00–M99›M00-M02›M02

ICD-10-CM M02.30
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M02.30 is a billable ICD-10-CM diagnosis code for Reiter's disease, unspecified site. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 545 through 547. 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 942 closely related codes. The code is flagged as an unspecified code, since codes identifying laterality exist in the same family. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Immune-mediated/reactive arthropathies.

For Medicare Advantage risk adjustment, M02.30 maps to CMS-HCC Category 94 (Systemic Lupus Erythematosus and Other Specified Systemic Connective Tissue Disorders) under the V28 model, adding a risk factor of about 0.268 for a community, non-dual, aged beneficiary in payment year 2026.

Code Identity

ICD-10-CM Code
M02.30
Billable Status
Yes — Valid for Submission
Code Describes
Reiter's disease, unspecified site
Short Description
Reiter's disease, unspecified site
Same as the full description in the CMS dataset.
Parent Code
Reiter's disease

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM00-M02Infectious arthropathies
CategoryM02Postinfective and reactive arthropathies
This CodeM02.30Reiter's disease, unspecified site

Code EditsBilling

Medicare Code Editor checks that affect claim validity for M02.30.

Unspecified codes exist in the ICD-10-CM classification for circumstances when documentation in the medical record does not provide the level of detail needed to support reporting a more specific code. However, in the inpatient setting, there should generally be very limited and rare circumstances for which the laterality (right, left, bilateral) of a condition is unable to be documented and reported. The following pages contain the list of unspecified ICD-10-CM diagnosis codes for which there is a more specific code to identify laterality (right, left, bilateral) within that code family.

Medicare Risk Adjustment (HCC)Billing

M02.30 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.

CMS-HCC V28 Category (Payment Model)
HCC 94— Systemic Lupus Erythematosus and Other Specified Systemic Connective Tissue Disorders
Payment HCC · PY 2026 one of 71 ICD-10-CM codes in this category
Risk Adjustment Factor (RAF) Weight
+0.268
community, non-dual, aged · ranges 0.196–0.297 across segments
Hierarchy
Superseded by HCC 93
a more severe related category takes the payment when both are reported
Prior Model (CMS-HCC V24)
HCC 40
V24 retired V28 pays 100% of MA risk scores since PY 2026
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)
RxHCC 83 — Rheumatoid Arthritis and Other Inflammatory Polyarthropathy
also risk-adjusts in the Part D prescription drug model (V08)

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.

  • Balanitis circinata
  • Circinate balanitis co-occurrent with reactive arthritis triad
  • Circinate vulvovaginitis co-occurrent with reactive arthritis triad
  • Conjunctivitis due to reactive arthritis triad
  • Juvenile reactive arthritis triad
  • Nail dystrophy co-occurrent with reactive arthritis triad
  • Oral lesion co-occurrent with reactive arthritis triad
  • Reactive arthritis of spine
  • Reactive arthritis triad
  • Urethritis due to reactive arthritis triad
  • Vaginitis associated with another disorder
  • Vulvitis associated with another disorder
  • Vulvovaginitis associated with another disorder

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 MUS008
Immune-mediated/reactive arthropathies
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Post-Streptococcal Arthritis|PSRA|PSRA|Post-Streptococcal Reactive Arthritis|Post-Streptococcal Reactive Arthritis

    the occurrence of arthritis after infection with group a streptococcus. it is non-migratory, protracted in course, and poorly responsive to anti-inflammatory agents. (from textbook of pediatric rheumatology, 6th ed. cassidy, petty, laxer, and lindsley)
  • Reactive Arthritis

    a form of inflammatory arthritis that results as a reaction to a bacterial infection outside the joint.

Patient EducationClinical

Infectious Arthritis

Most kinds of arthritis cause pain and swelling in your joints. Joints are places where two bones meet, such as your elbow or knee. Infectious arthritis is an infection in the joint. The infection comes from a bacterial, viral, or fungal infection that spreads from another part of the body. Symptoms of infectious arthritis include:

Read the full article at MedlinePlus

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

Convert M02.30 to ICD-9-CMHistory

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

ICD-9-CM
099.3 Reiter's disease
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.
ICD-9-CM
711.10 Reiter arthritis-unspec
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.

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 M02.30Overview

What is the ICD-10 code for Reiter's disease, unspecified site?

The ICD-10-CM code for Reiter's disease, unspecified site is M02.30 (sometimes written as M0230). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Is M02.30 (Reiter's disease) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report Reiter's disease, unspecified site on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does M02.30 group to?

When Reiter's disease, unspecified site is the principal diagnosis on an inpatient stay, it groups to MS-DRG 545, 546, 547, with relative weights from 0.8362 to 2.4817 depending on complications. Higher weights mean higher Medicare reimbursement.

Is M02.30 a CC or MCC?

CMS lists M02.30 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 942 closely related codes in its exclusion list.

What is the ICD-9 equivalent of M02.30?

Under the General Equivalence Mappings, Reiter's disease, unspecified site converts to ICD-9-CM 099.3 (Reiter's disease) and 711.10 (reiter arthritis-unspec). The mapping is approximate, so confirm the match fits the documentation.

What HCC is M02.30?

M02.30 (Reiter's disease, unspecified site) maps to CMS-HCC Category 94 (Systemic Lupus Erythematosus and Other Specified Systemic Connective Tissue Disorders), commonly written as HCC 94, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2026. It mapped to HCC 40 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 83.

Does M02.30 risk-adjust for Medicare Advantage payment?

Yes. When documented and reported on a Medicare Advantage encounter, M02.30 adds a risk adjustment factor of about 0.268 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.196 to 0.297 depending on the payment segment). A more severe related category (HCC 93) supersedes it when both are reported. See the full factor table on the HCC 94 category page.