M02.869

Other reactive arthropathies, unspecified knee

FY2027Chapter 13: Diseases of the musculoskeletal system and connective tissue/M00–M02 Infectious arthropathies

BillableComplete code, valid to report

M02.869 (also written M02869) is a billable ICD-10-CM diagnosis code for other reactive arthropathies, unspecified knee. It is part of the FY2027 code set, effective October 1, 2026. It is one of the 121 codes in category M02 (Postinfective and reactive arthropathies). Its coding notes include a Code first instruction, 8 Excludes1 entries and 10 Excludes2 entries.

Code first

If the underlying condition listed here is present and known, sequence it first.

Inherited from M02 Postinfective and reactive arthropathies
  • underlying disease, such as:
    • congenital syphilis [Clutton's joints] (A50.5)
    • enteritis due to Yersinia enterocolitica (A04.6)
    • infective endocarditis (I33.0)
    • viral hepatitis (B15-B19)

Excludes1

Not coded here. The listed conditions generally should not be reported together.

Inherited from M02 Postinfective and reactive arthropathies
  • Behçet's disease (M35.2)
  • direct infections of joint in infectious and parasitic diseases classified elsewhere (M01.-)
  • postmeningococcal arthritis (A39.84)
  • mumps arthritis (B26.85)
  • rubella arthritis (B06.82)
  • syphilis arthritis (late) (A52.77)
  • rheumatic fever (I00)
  • tabetic arthropathy [Charcôt's] (A52.16)

Excludes2

Not included here. Both codes may be reported if the patient has both conditions.

Also from chapter/block level (10 notes)
Inherited from Chapter 13 Diseases of the musculoskeletal system and connective tissue
  • 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)

Care settings

How CMS programs treat this code. These are CMS claim edits and list entries, not coverage or eligibility rules.

Hospice: not accepted as primary

Not accepted as the principal diagnosis on a hospice claim (bill types 081x and 082x). The Integrated OCE returns an edit for this code.
Reason: Manifestation code. Report the underlying condition first (see the Code first note).

Source: CMS Integrated Outpatient Code Editor (IOCE) v27.3, effective October 1, 2026, edit 86

Hospital CC

Counts as a complication or comorbidity (CC) when reported as a secondary diagnosis on an inpatient claim. It does not count when the principal diagnosis is one of the 942 codes in its exclusion list. Some MS-DRGs also ignore a CC or MCC that defines the DRG.

Source: CMS MS-DRG Definitions Manual v44, effective October 1, 2026, Appendix C

Notes

Also from chapter/block level (4 notes)
Inherited from M00–M02 Infectious arthropathies
  • 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.
Inherited from Chapter 13 Diseases of the musculoskeletal system and connective tissue
  • Use an external cause code following the code for the musculoskeletal condition, if applicable, to identify the cause of the musculoskeletal condition