Inflammatory polyarthropathies

Felty's syndrome coded at the unspecified-site level — rheumatoid arthritis with positive rheumatoid factor, splenomegaly, and granulocytopenia/neutropenia, where the affected joint site is not documented.

Felty's syndrome affecting multiple joint sites simultaneously — the triad of seropositive rheumatoid arthritis, splenomegaly, and granulocytopenia documented across more than one anatomical region.

Rheumatoid lung disease occurring in a patient with seropositive rheumatoid arthritis (RF-positive), where the specific joint site is not documented or identified.

Rheumatoid lung disease occurring concurrently with seropositive rheumatoid arthritis affecting multiple joint sites simultaneously, captured under a single billable code when bilateral or polyarticular involvement is present alongside pulmonary manifestation.

Rheumatoid vasculitis occurring alongside seropositive rheumatoid arthritis, coded without specification of which joint site is involved.

Rheumatoid vasculitis with seropositive rheumatoid arthritis affecting multiple joint sites simultaneously, representing a severe systemic complication where vascular inflammation is present alongside polyarticular disease.

Rheumatoid heart disease — encompassing rheumatoid carditis, endocarditis, myocarditis, and pericarditis — occurring in a patient with seropositive rheumatoid arthritis, where the joint site affected is not specified in the documentation.

Seropositive rheumatoid arthritis affecting the heart (carditis, endocarditis, myocarditis, or pericarditis) in a patient whose joint disease involves multiple anatomical sites simultaneously.

M05.40 captures rheumatoid myopathy occurring as a systemic manifestation of rheumatoid factor-positive rheumatoid arthritis when no specific joint site is documented.

Rheumatoid myopathy occurring as an extraarticular manifestation of seropositive rheumatoid arthritis, documented at multiple joint sites simultaneously.

Rheumatoid polyneuropathy occurring alongside rheumatoid arthritis, reported when the affected joint site is not specified in the clinical documentation.

Rheumatoid polyneuropathy with seropositive (rheumatoid factor–positive) rheumatoid arthritis affecting multiple joint sites simultaneously.

Rheumatoid arthritis with positive rheumatoid factor affecting an unspecified joint site, with documented involvement of other organs or body systems beyond the joints themselves.

Seropositive rheumatoid arthritis affecting multiple joint sites simultaneously, with documented involvement of one or more organs or body systems beyond the joints themselves.

Seropositive rheumatoid arthritis confirmed by positive rheumatoid factor, with no documented specific joint site and no evidence of extra-articular organ or systemic involvement.

Seropositive rheumatoid arthritis affecting multiple joints simultaneously, confirmed by positive rheumatoid factor, with no documented involvement of organs or organ systems beyond the musculoskeletal system.

Rheumatoid arthritis confirmed by positive rheumatoid factor, affecting a site not individually enumerated in the M05.7 subcategory, with no documented organ or systemic involvement.

Seropositive rheumatoid arthritis that does not fit the more specifically defined M05 subcategories, with the affected anatomical site undocumented or unspecified in the clinical record.

Rheumatoid arthritis confirmed by positive rheumatoid factor (RF) seropositivity, classified under the 'other' subcategory of M05.8, affecting multiple joint sites simultaneously rather than a single anatomic location.

Rheumatoid arthritis with a confirmed positive rheumatoid factor affecting a site not captured by the anatomically specific M05.8x subcodes — such as the temporomandibular joint, cricoarytenoid joint, or other atypical locations.

Seronegative rheumatoid arthritis where the affected joint site is not documented or cannot be specified — used when RF (rheumatoid factor) is negative or absent from lab results and no single anatomic site is identified.

Seronegative rheumatoid arthritis affecting the vertebral column, confirmed without detectable rheumatoid factor on laboratory testing.

Seronegative rheumatoid arthritis affecting three or more distinct joint regions simultaneously, with negative rheumatoid factor lab results documented in the medical record.

Seronegative rheumatoid arthritis affecting a joint or anatomical site that doesn't fit any of the named site subcategories under M06.0 — not shoulder, elbow, wrist, hand, hip, knee, ankle/foot, vertebrae, or multiple sites.

Rheumatoid bursitis at an unspecified anatomical site — bursal inflammation occurring in the context of rheumatoid disease where the treating provider has not documented or identified the specific joint location.

Rheumatoid bursitis affecting the vertebral region — bursal inflammation along the spine occurring in the context of rheumatoid disease.

Rheumatoid bursitis affecting two or more anatomically distinct joint sites simultaneously, classified under other rheumatoid arthritis (M06) when bursal inflammation is the primary manifestation across multiple regions.

Rheumatoid nodule at an unspecified anatomic site — a firm subcutaneous granulomatous lesion associated with rheumatoid arthritis when the treating provider has not documented or identified the specific body location.

M06.38 identifies a rheumatoid nodule located at the vertebrae, classified under other rheumatoid arthritis without rheumatoid factor involvement as the primary driver.

Rheumatoid nodule, multiple sites — subcutaneous or deep-tissue nodules associated with rheumatoid arthritis occurring at more than one anatomical location simultaneously.

M06.80 classifies a form of rheumatoid arthritis that falls outside the specifically named RA subtypes (seronegative, Still's disease, rheumatoid bursitis, rheumatoid nodule) but without documentation of a specific anatomical site.

Inflammatory arthritis of the vertebral joints classified as 'other specified' rheumatoid arthritis — meaning the provider has documented a specific RA subtype that does not map to seropositive (M05) or seronegative (M06.0) categories, with the spine as the primary affected site.

M06.89 captures other specified rheumatoid arthritis affecting multiple joint sites simultaneously, used when the RA subtype does not carry a positive rheumatoid factor and the polyarticular presentation spans joints that cannot be collapsed into a single anatomic site code.

Other specified rheumatoid arthritis affecting a site that does not map to any of the named anatomical locations in the M06.8 subcategory — used when the involved joint or structure is documented but falls outside shoulder, elbow, wrist, hand, hip, knee, ankle/foot, vertebrae, or multiple sites.

Inflammatory joint disease linked to an underlying gastrointestinal condition — such as Crohn's disease or ulcerative colitis — where the specific joint site has not been documented or identified.

Inflammatory arthritis of the spinal vertebrae occurring as a direct manifestation of an underlying inflammatory bowel disease, such as Crohn's disease or ulcerative colitis.

Enteropathic arthropathy affecting multiple joint sites simultaneously, coded when inflammatory bowel disease (Crohn's disease or ulcerative colitis) drives joint involvement across more than one anatomical region.

Juvenile rheumatoid arthritis (with or without rheumatoid factor) in a patient under 16, where the subtype and affected joint site are both undocumented or indeterminate at the time of coding.

M08.08 identifies juvenile rheumatoid arthritis of unspecified type with documented vertebral involvement in a patient under 16 years of age at onset.

Unspecified juvenile rheumatoid arthritis affecting multiple joint sites simultaneously, where the specific subtype cannot be determined from available documentation.

Juvenile rheumatoid arthritis (unspecified type, with or without rheumatoid factor) affecting a documented anatomical site that does not match any of the other specific site subcode options in the M08.0 family.

Systemic-onset juvenile rheumatoid arthritis (Still's disease) coded without specification of which joint or body site is involved — use when systemic features are documented but joint site is not.

M08.28 identifies systemic-onset juvenile rheumatoid arthritis (Still's disease, juvenile onset) where the primary documented joint involvement is the vertebrae, in a patient whose disease onset occurred before age 16.

Systemic-onset juvenile rheumatoid arthritis (Still's disease in children) involving multiple joint sites simultaneously, requiring both systemic features and multi-site joint documentation to support the code.

Juvenile rheumatoid arthritis with systemic onset affecting a documented but anatomically atypical joint site not captured by the standard laterality-based subcodes in the M08.2x series.

Pauciarticular juvenile rheumatoid arthritis affecting an unspecified joint site — meaning four or fewer joints are involved and the specific joint(s) have not been documented in the clinical record.

Pauciarticular juvenile rheumatoid arthritis localized to the vertebrae — inflammatory arthritis in a patient under 16 years old affecting four or fewer joints total, with the spine as the documented site of involvement.

Pauciarticular juvenile rheumatoid arthritis affecting an anatomical site not captured by any other specific site code in the M08.4 subcategory — used when the affected joint is documented but doesn't map to the standard laterality options.

M08.80 classifies juvenile arthritis that falls outside the specifically defined subtypes (systemic, pauciarticular, seronegative polyarticular, seropositive polyarticular, psoriatic, or enthesitis-related) and where no specific joint site is documented or identifiable.

M08.88 classifies other juvenile arthritis affecting a site that falls outside the named joint locations in the M08.8x series — such as the temporomandibular joint, sacroiliac joint, or another anatomically distinct site not captured by shoulder through ankle/foot codes.

Other juvenile arthritis affecting multiple joint sites simultaneously, used when the specific JA subtype does not fit a more defined M08 category and involvement spans more than one discrete anatomical region.

Juvenile arthritis of unspecified type affecting an unspecified anatomical site — the least specific billable code in the M08.9x family, used only when both the arthritis subtype and the involved joint are undocumented.

M08.98 identifies juvenile arthritis of unspecified type affecting the vertebrae in a patient under age 16 at disease onset, where the specific arthritis subtype has not been determined or documented.

M08.99 identifies juvenile arthritis of unspecified type involving multiple joint sites simultaneously in a patient under 16 years of age at onset, where the specific subtype of juvenile arthritis has not been documented.

Juvenile arthritis, type unspecified, affecting a site that does not correspond to any standard anatomical site listed elsewhere in the M08.9x subcode set — such as the temporomandibular joint, sternoclavicular joint, or sacroiliac joint.

M10.00 identifies idiopathic (primary) gout without a documented anatomic site — no laterality, no specific joint named in the record.

Idiopathic gout affecting the vertebral joints, with no identified secondary cause such as drug exposure, lead toxicity, or renal impairment.

Idiopathic gout affecting multiple joints simultaneously, where no identifiable secondary cause (such as medication, renal disease, or lead exposure) underlies the hyperuricemia and crystal deposition.

Gout caused by lead toxicity, assigned when the affected joint or anatomical site is not documented or cannot be specified.

Gout affecting the vertebrae caused by lead toxicity, classified under secondary gout due to a toxic substance rather than idiopathic or metabolic origin.