Secondary gout involving multiple joint sites simultaneously, where the hyperuricemia and resulting gouty arthritis stem from an identifiable underlying condition other than lead exposure, renal impairment, or drug use.

Documentation tips

What should appear in the chart to support M10.49.

Source · Editorial brief grounded in 6 cited references ↓

• Name each affected joint explicitly (e.g., right first MTP and left wrist) — 'multiple joints' without specificity is insufficient to justify this code over a single-site code.
• Document the underlying cause of secondary gout by diagnosis, not just the lab finding; a serum urate level alone does not establish secondary etiology.
• Record whether this is an acute flare or chronic/tophaceous presentation — chronic gout maps to M1A.49, not M10.49.
• Sequence the causative condition first per the M10.4 'Code First associated condition' instruction and note that linkage explicitly in the encounter documentation.
• Capture any associated organ manifestations (renal calculi, cardiomyopathy, glomerulonephritis) so coders can append the required additional codes at the M10 category level.
• Distinguish 'other secondary gout' from drug-induced (M10.1x), lead-induced (M10.2x), and renal-impairment gout (M10.3x) — document that none of these specific etiologies apply if coding M10.49.

Related CPT procedures

Procedure codes commonly billed with M10.49. Linking the right diagnosis to the right procedure is what establishes medical necessity.

Source · CMS LCDs · AAOS specialty guidance · claims-pattern analysis

Common coding pitfalls

The recurring mistakes coders make with M10.49 and adjacent codes.

Source · Editorial brief grounded in CDC ICD-10-CM tabular guidance, AAOS coding references, and cited references ↓

• Sequencing M10.49 first when a 'Code First' underlying condition is present — the causative systemic disease belongs in the primary position.
• Using M10.49 for chronic tophaceous gout at multiple sites — that presentation requires M1A.49, since M10 is limited to acute gout/gout flares and chronic gout is Excludes2.
• Defaulting to M10.9 (unspecified gout) when the record documents both a secondary etiology and polyarticular involvement — M10.49 is the correct billable code in that scenario.
• Conflating renal-impairment secondary gout (M10.39) with 'other' secondary gout (M10.49) — if chronic kidney disease or renal dysfunction is the documented cause, use M10.3x, not M10.4x.
• Assigning M10.49 when only one joint is affected — use the appropriate single-site M10.4x code (M10.40–M10.47) when laterality and site are documented.

Clinical context

Source · Editorial summary grounded in 6 cited references ↓

Sibling codes

Other billable codes under M10.4 (laterality / anatomic variants).