ICD-10-CM · Spine

M10.18

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

Verified May 8, 2026 · 7 sources ↓

Status: Billable
Chapter: 13
Related CPT: 9
Region: Spine

Drawn from CDCAAPCICD10DataIcdcodesOutsourcestrategies

Documentation tips

What should appear in the chart to support M10.18.

Source · Editorial brief grounded in 7 cited references ↓

Document the confirmed or suspected source of lead exposure (occupational, environmental, prior paint exposure, etc.) to support coding T56.0- as the first-listed toxic effect code.
Specify the vertebral level or spinal region involved (cervical, thoracic, lumbar, sacral) — M10.18 covers all vertebrae but the clinical record should identify the affected segment for medical necessity.
Record imaging findings that support spinal gout: urate crystal deposition on CT or MRI, joint space changes, or erosions at vertebral facets or intervertebral disc spaces.
Note whether this is an acute flare versus a chronic presentation — if tophi are present or the condition is longstanding, reassess whether M1A.- series codes apply instead.
Document serum uric acid levels and, where performed, synovial fluid analysis or DECT findings to validate the gout diagnosis and support audit defense.

Related CPT procedures

Procedure codes commonly billed with M10.18. Linking the right diagnosis to the right procedure is what establishes medical necessity.

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

72020 $23.71

Single-view radiologic examination of the spine at a specified level.

72100 $40.42

Radiologic examination of the lumbosacral spine capturing two or three views, used to evaluate the lumbar vertebrae and sacrum for injury, degeneration, or structural abnormality.

72110 $53.44

Radiologic examination of the lumbar spine (lumbosacral) with a minimum of four views, including oblique and/or bending views.

72148 $191.72

Non-contrast MRI of the lumbar spine used to evaluate disc pathology, spinal stenosis, nerve root compression, and other structural abnormalities without administration of contrast material.

20610 $68.81

Aspiration and/or injection of a major joint or bursa (shoulder, hip, knee, or subacromial bursa) performed without ultrasound guidance.

72070 $33.07

Two-view radiologic examination of the thoracic spine, including AP and lateral projections of the 12 thoracic vertebrae.

72080 $35.07

Radiologic examination of the thoracolumbar junction (where the thoracic and lumbar spine meet), requiring a minimum of two views.

99213 $95.19

Established patient office or outpatient visit requiring 20–29 minutes of total time or low-complexity medical decision-making.

99214 $135.61

Office visit for an established patient requiring moderate-complexity medical decision making (MDM), or 30–39 minutes of total provider time on the date of service.

Common coding pitfalls

The recurring mistakes coders make with M10.18 and adjacent codes.

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

Failing to sequence T56.0- (toxic effects of lead) before M10.18 — the 'Code First' instruction at M10.1 is mandatory, not optional; M10.18 cannot be the first-listed diagnosis.
Using M10.18 when the clinical picture is chronic gout — the Excludes2 note at M10 directs chronic gout to M1A.-, and using M10.18 for a long-standing case with tophi is a misclassification.
Defaulting to unspecified gout (M10.9) when the provider has documented lead-induced etiology and vertebral involvement — M10.18 is the correct billable code and unspecified coding increases audit risk.
Confusing spinal gout with idiopathic gout of the vertebrae (M10.08) — the lead-induced etiology changes both the code and the required toxic-effect sequencing.
Omitting the T56.0- specificity extension; T56.0 is the lead category but the dash indicates additional characters are required — verify the correct 7th-character extension for the encounter type.

Clinical context

Source · Editorial summary grounded in 7 cited references ↓

M10.18 identifies acute gout localized to the vertebrae when the underlying cause is lead exposure or lead toxicity. This is a secondary gout diagnosis — the hyperuricemia is driven by lead's interference with renal urate excretion, not primary metabolic dysfunction. Spinal gout is rare but documented; it can mimic disc disease or inflammatory spondyloarthropathy, making the etiologic link to lead exposure critical for correct coding.

The ICD-10-CM tabular instruction at parent code M10.1 requires sequencing: code first the toxic effects of lead and its compounds (T56.0-) before assigning M10.18. This is a mandatory 'Code First' note — M10.18 is never the first-listed code when a toxic lead exposure is the underlying cause. Skipping T56.0- will trigger a sequencing error.

If the gout has transitioned to a chronic pattern with tophi or radiographic erosions, do not use M10.18 — use the appropriate M1A.- code instead. The Excludes2 note at M10 explicitly excludes chronic gout (M1A.-), meaning chronic and acute lead-induced gout are coded from entirely different categories. Confirm acuity before assigning M10.18.

Sibling codes

Other billable codes under M10.1 (laterality / anatomic variants).

M10.19

Lead-induced gout, multiple sites

M10.10

Lead-induced gout, unspecified site

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 7 cited references ↓

01Does M10.18 require a secondary code?

Yes. The 'Code First' instruction at parent code M10.1 requires T56.0- (toxic effects of lead and its compounds) to be sequenced before M10.18. Assigning M10.18 alone without T56.0- is a sequencing error.

02When should I use M1A.- instead of M10.18 for lead-induced vertebral gout?

Use M1A.- codes when the gout is chronic — defined by the presence of tophi, radiographic joint erosions, or a longstanding recurrent pattern. M10.18 applies to acute gout only. The Excludes2 note at M10 makes this distinction mandatory, not discretionary.

03Is spinal gout common enough to warrant its own code?

Spinal gout is uncommon but recognized — urate crystals can deposit in facet joints, ligamentum flavum, or intervertebral disc spaces. M10.18 exists specifically for this presentation when lead toxicity is the identified cause.

04What specificity is needed for the T56.0- toxic effect code?

T56.0 covers toxic effects of lead and its compounds, but the dash indicates additional characters are required. You must assign the full code with the appropriate 7th-character extension: A (initial encounter), D (subsequent encounter), or S (sequela), matching the encounter type.

05Can M10.18 be used if lead exposure is suspected but not confirmed?

Coding guidelines require physician documentation of the diagnosis. If the provider has documented lead-induced gout, code it. If lead exposure is only suspected and the provider has not confirmed the causal link, query before assigning M10.18 — defaulting to M10.9 (unspecified gout) is the fallback without confirmed etiology.

06What imaging supports a diagnosis of vertebral gout for coding purposes?

CT showing hyperdense periarticular deposits, MRI demonstrating tophaceous masses at facet joints or disc spaces, or dual-energy CT (DECT) confirming urate deposition all support the diagnosis. Document the modality and findings explicitly in the record.

07Is there a laterality requirement for M10.18?

No. M10.18 does not use laterality characters — vertebral involvement is coded without a right/left distinction. Laterality applies to limb-based gout codes within M10, not to the vertebrae subcode.

Sources & references

Editorial content was developed using the following public sources. Last verified May 8, 2026.

Mira AI Scribe

Mira AI Scribe captures the documented lead exposure source, affected vertebral level, serum uric acid result, imaging findings (CT/MRI urate deposition, erosions), and whether the presentation is acute versus chronic. Capturing this prevents downcoding to M10.9, flags the mandatory T56.0- sequencing requirement, and ensures the 'Code First' toxic-effect instruction is met before M10.18 is assigned.

See how Mira captures M10.18 documentation