2027 ICD-10-CM Diagnosis Code M02.9Reactive arthropathy, unspecified
ICD-10-CM Codes›M00–M99›M00-M02›M02
- Billable — Valid for Submission
- Risk Adjusts — HCC 92
- Not Chronic
M02.9 is a billable ICD-10-CM diagnosis code for reactive arthropathy, unspecified. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 553 through 554. The code is a manifestation code that cannot be reported as the principal diagnosis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Immune-mediated/reactive arthropathies.
For Medicare Advantage risk adjustment, M02.9 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 2027.
Code Identity
Code Classification
Code EditsBilling
Medicare Code Editor checks that affect claim validity for M02.9.
Medicare Risk Adjustment (HCC)Billing
M02.9 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 2027.
Source: CMS Payment Year 2027 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.
- Arthritis due to and following viral infection
- Arthritis due to parasitic infection
- Arthropathy associated with bacterial disease
- Arthropathy associated with viral disease
- Inflammation of pubic symphysis
- Juvenile reactive arthritis
- Mycobacterial postinfective arthritis
- Parasitic postinfectious arthritis
- Post-bacterial arthropathy
- Post-genitourinary infection reactive arthritis
- Postinfectious arthritis due to Yersinia enterocolitica enteritis
- Post-infective arthritis
- Post-streptococcal reactive arthritis
- Reactive arthritis
- Reactive arthritis due to and following infective urethritis
- Reactive arthritis of symphysis pubis
- Urethritis co-occurrent with reactive arthritis
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to M02.9: its own notes plus those printed at M02, block M00-M25, block M00-M02, and Chapter 13. A note printed at a category, block or chapter applies to every code under it.
Includes
Further defines, or gives examples of, the content of the category.
- Disorders affecting predominantly peripheral (limb) joints
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
- arthropathic psoriasis (L40.5-)
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- compartment syndrome (traumatic) (T79.A-)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
Code First
The underlying condition named in the note is sequenced before this code.
Notes
General instructions on how these codes are used.
- This block comprises arthropathies due to microbiological agents. Distinction is made between the following types of etiological relationship:
- a) direct infection of joint, where organisms invade synovial tissue and microbial antigen is present in the joint;
- b) indirect infection, which may be of two types: a reactive arthropathy, where microbial infection of the body is established but neither organisms nor antigens can be identified in the joint, and a postinfective arthropathy, where microbial antigen is present but recovery of an organism is inconstant and evidence of local multiplication is lacking.
- Use an external cause code following the code for the musculoskeletal condition, if applicable, to identify the cause of the musculoskeletal condition
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name M02.9, its category, or a range that includes it.
Excludes1 1
These codes carry an Excludes1 note naming M02.9: they are not reported together with it, unless the two conditions are unrelated.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Arthropathy See Also: Arthritis; M12.9
reactive M02.9
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
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 M02.9 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About M02.9Overview
What is the ICD-10 code for reactive arthropathy, unspecified?
The ICD-10-CM code for reactive arthropathy, unspecified is M02.9 (sometimes written as M029). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is M02.9 (Postinfective and reactive arthropathies) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report reactive arthropathy, unspecified on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does M02.9 group to?
On inpatient claims, reactive arthropathy, unspecified maps to MS-DRG 554, 553, with relative weights from 0.8328 to 1.2492 depending on complications. Higher weights mean higher Medicare reimbursement.
Can M02.9 be a principal diagnosis?
No. This is a manifestation code: reactive arthropathy, unspecified describes the manifestation of an underlying disease rather than the disease itself, so the underlying condition is sequenced first.
Can M02.9 be reported with M35.2?
Not as a rule. The Excludes1 note at M02, which applies to M02.9, lists "Behçet's disease (M35.2)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
What HCC is M02.9?
M02.9 (reactive arthropathy, unspecified) 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 2027. 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 M02.9 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, M02.9 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.
