Acute gout flare triggered by a medication or other pharmacologic agent, reported when the affected joint site is not documented or cannot be specified.
Verified May 8, 2026 · 5 sources ↓
- Status
- Billable
- Chapter
- 13
- Related CPT
- 4
- Region
- General
Documentation tips
What should appear in the chart to support M10.20.
Source · Editorial brief grounded in 5 cited references ↓
- Record the specific joint affected — even a general descriptor like 'first MTP joint' or 'knee' lets you move to a site-specific M10.2x code instead of the unspecified M10.20.
- Identify the offending drug by generic name and route; this is required to assign the correct T36–T50 adverse effect code that must accompany M10.20.
- Distinguish acute flare from chronic gout in the assessment — 'gout flare' supports M10.20, while 'chronic gout' or 'gout with tophi' points to M1A.2-.
- Document the causal relationship explicitly: 'gout flare secondary to hydrochlorothiazide' rather than 'gout; patient takes HCTZ' — the causal link must be provider-stated, not coder-inferred.
- Note serum urate level and any synovial fluid crystal analysis in the record; these support clinical validity during audit review.
Related CPT procedures
Procedure codes commonly billed with M10.20. 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 M10.20 and adjacent codes.
Source · Editorial brief grounded in CDC ICD-10-CM tabular guidance, AAOS coding references, and cited references ↓
- Omitting the mandatory T36–T50 adverse effect code: M10.20 must be accompanied by a drug identification code with 5th or 6th character 5; submitting M10.20 alone is incomplete per Tabular List instructions.
- Using M10.20 when a specific joint site is documented: if the note says 'right knee,' the correct code is M10.261, not M10.20 — 'unspecified site' is not a substitute for reading the record.
- Confusing drug-induced gout (M10.2-) with lead-induced gout (M10.1-); lead exposure is coded separately and is not a pharmaceutical adverse effect scenario.
- Assigning M10.20 for chronic drug-induced gout instead of the appropriate M1A.2- code — M10.20 describes an acute presentation only.
- Sequencing the T-code first: M10.20 should be listed as the principal or first-listed diagnosis; the T36–T50 adverse effect code follows as an additional code.
Clinical context
Source · Editorial summary grounded in 5 cited references ↓
M10.20 is the catch-all code for drug-induced gout when the clinical note does not identify a specific joint. The M10.2x subcategory covers gout precipitated by medications — most commonly diuretics (thiazides, loop diuretics), low-dose aspirin, cyclosporine, pyrazinamide, and niacin — that elevate serum urate or impair renal urate excretion. When the affected site is documented, use the site-specific codes instead: M10.21x (shoulder), M10.22x (elbow), M10.23x (wrist), M10.24x (hand), M10.25x (hip), M10.26x (knee), M10.27x (ankle and foot), M10.28 (vertebrae), M10.29 (multiple sites). M10.20 is valid only when the provider's note genuinely omits joint location.
The Tabular List instructs coders to add a secondary code from T36–T50 with a 5th or 6th character of 5 to identify the offending drug and flag it as an adverse effect. This dual-coding requirement is mandatory, not optional — skip it and the claim lacks the pharmacologic causation link that payers and auditors expect. Sequence M10.20 first, then the T-code adverse effect code.
Do not use M10.20 for chronic drug-induced gout; the M1A.2- subcategory handles that. The Excludes2 note at the M10 block level confirms M1A.- codes can be assigned separately when both acute and chronic conditions coexist, but M10.20 itself represents an acute flare, not a chronic disease state. If the record describes tophi or a pattern of recurrent disease, query the provider about chronic gout before defaulting to M10.20.
Sibling codes
Other billable codes under M10.2 (laterality / anatomic variants).
Frequently asked questions
Source · Generated from the editorial pipeline, verified against 5 cited references ↓
01Is M10.20 billable on its own?
02Which code takes priority in sequencing — M10.20 or the T-code?
03When should I use M1A.20 instead of M10.20?
04The note documents 'gout flare' but doesn't name a joint. Can I query the provider?
05Does M10.20 apply to gout triggered by chemotherapy agents?
06How does drug-induced gout (M10.2-) differ from gout due to renal impairment (M10.3-)?
07What MS-DRGs does M10.20 map to?
Sources & references
Editorial content was developed using the following public sources. Last verified May 8, 2026.
- 01CDC ICD-10-CM Tabular List 2026 (effective Oct 1, 2025)
- 02icd10data.comhttps://www.icd10data.com/ICD10CM/Codes/M00-M99/M05-M14/M10-/M10.20
- 03aapc.comhttps://www.aapc.com/codes/icd-10-codes/M10.20
- 04cms.govhttps://www.cms.gov/files/document/fy-2025-icd-10-cm-coding-guidelines.pdf
- 05pmc.ncbi.nlm.nih.govhttps://pmc.ncbi.nlm.nih.gov/articles/PMC10563586/
Mira AI Scribe
Mira AI Scribe captures the treating joint, the suspected causative medication (name, dose, duration), the provider's explicit statement linking the drug to the gout flare, and any serum urate or synovial fluid findings documented during the encounter. This detail drives site-specific code selection over M10.20 and satisfies the mandatory T36–T50 adverse effect pairing — preventing a claim rejection for an incomplete dual-code submission.
See how Mira captures M10.20 documentation