ICD-10-CM · Multi-region

M06.39

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

Verified May 8, 2026 · 6 sources ↓

Status
Billable
Chapter
13
Related CPT
9
Region
Multi-region
Drawn from CDCICD10DataAAPCCMSFiles

Documentation tips

What should appear in the chart to support M06.39.

Source · Editorial brief grounded in 6 cited references ↓

  • Name each nodule location explicitly (e.g., right olecranon, left Achilles tendon) — 'multiple sites' must be supported by at least two distinct documented locations.
  • Distinguish the nodule finding from the underlying RA diagnosis; document both the rheumatoid nodules (M06.39) and the RA type (e.g., M05.79 or M06.09) when both are managed in the encounter.
  • Record rheumatoid factor status and anti-CCP results in the note — this determines which RA code pairs with M06.39 and prevents audit flags from undifferentiated RA coding.
  • Document nodule characteristics (size, consistency, mobility, tenderness) to support clinical necessity for imaging, biopsy, or surgical excision if performed.
  • If a nodule has been biopsied or excised, link the pathology result confirming rheumatoid nodule histology back to M06.39 in the problem list.

Related CPT procedures

Procedure codes commonly billed with M06.39. 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 M06.39 and adjacent codes.

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

  • Coding M06.39 alone without a separate underlying RA code misses the full clinical picture and may reduce medical necessity support for biologics or DMARDs.
  • Using M06.09 (seronegative RA, multiple sites) when the intent is to capture nodules — M06.09 codes the arthritis subtype, not the nodular manifestation.
  • Defaulting to M06.9 (RA, unspecified) when the provider has explicitly documented rheumatoid nodules at multiple sites — that documentation supports the more specific M06.39.
  • Assigning a single-site M06.3x code (e.g., M06.31 for shoulder) when nodules are present bilaterally or at multiple distinct regions — M06.39 is the correct choice for multi-site involvement.
  • Confusing M06.39 with M06.89 (other specified rheumatoid arthritis, multiple sites) — M06.89 captures other specified RA variants, not the nodular complication specifically.

Clinical context

Source · Editorial summary grounded in 6 cited references ↓

M06.39 captures rheumatoid nodules documented at multiple sites in the same patient. Rheumatoid nodules are firm, non-tender subcutaneous masses that develop in the setting of rheumatoid arthritis, most commonly over pressure points such as the olecranon, finger joints, Achilles tendon, and sacrum. When nodules are present at two or more distinct locations, M06.39 is the correct code — not a single-site M06.3x code repeated per location.

This code sits within the M06.3 parent category (Rheumatoid nodule) and is used regardless of rheumatoid factor status — it describes the nodular manifestation, not the serological subtype of RA. If the underlying RA diagnosis itself requires separate coding (e.g., M05.79 for seropositive RA at multiple sites, or M06.09 for seronegative RA at multiple sites), code that separately and sequence it appropriately. M06.39 codes the nodular complication.

Do not confuse M06.39 with M06.09 (seronegative RA, multiple sites) or M06.89 (other specified rheumatoid arthritis, multiple sites). The key distinguishing factor is that M06.39 is specifically for the nodular manifestation — the physical finding of rheumatoid nodules — not for the arthritis diagnosis itself. Documentation must explicitly identify the lesions as rheumatoid nodules; a general RA note without nodule documentation does not support this code.

Sibling codes

Other billable codes under M06.3 (laterality / anatomic variants).

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 6 cited references ↓

01Can M06.39 be used as a standalone code, or must it be paired with an RA diagnosis code?
M06.39 can be billed as a standalone billable code, but best practice is to also code the underlying RA type (e.g., M05.79 for seropositive RA, M06.09 for seronegative RA at multiple sites) when both are documented and managed, since payers often require the primary disease to support medical necessity for associated treatments.
02How many sites must be documented to use M06.39 instead of a single-site M06.3x code?
At least two distinct anatomical locations must be documented as having rheumatoid nodules. If only one site is documented, use the appropriate single-site M06.3x code (e.g., M06.31 for shoulder, M06.34 for hand).
03Does rheumatoid factor status affect whether M06.39 is the right code?
No — M06.39 codes the nodular manifestation regardless of serological status. Rheumatoid factor status determines which RA code (M05.x vs. M06.x) you assign for the arthritis itself, not the nodule code.
04Is M06.39 appropriate when nodules are bilateral at the same joint (e.g., both elbows)?
Yes. Bilateral involvement at the same anatomical structure (e.g., both olecranon bursae) qualifies as multiple sites for the purposes of M06.39, provided both locations are explicitly documented.
05What CPT codes commonly pair with M06.39 in orthopedic or hand surgery encounters?
Excision of a rheumatoid nodule typically pairs with soft-tissue excision CPT codes such as 26160 (excision of lesion of tendon sheath or joint capsule, hand/finger) or 25111 (excision of ganglion, wrist). Imaging to evaluate nodule extent may involve 73221 (MRI wrist) or 73721 (MRI lower extremity joint). Confirm CPT-to-diagnosis linkage in the claim.
06Can M06.39 be used for nodular lesions found incidentally on imaging without a prior RA diagnosis on the chart?
Only if the treating provider documents a diagnosis of rheumatoid nodule(s) based on clinical judgment — ICD-10-CM requires physician-assigned diagnoses, not coder interpretation of imaging findings. If RA is not yet established, the lesion may need to be coded as an unspecified soft-tissue mass (M79.89x) until confirmed.
07How does M06.39 interact with biologic therapy authorization?
Payers reviewing prior authorization for biologics (e.g., TNF inhibitors) expect the primary RA code (M05.x or M06.x) as the lead diagnosis. M06.39 supports clinical severity documentation — rheumatoid nodules indicate active or advanced disease — but sequence the RA code first on the claim to align with payer medical necessity criteria.

Mira AI Scribe

The Mira AI Scribe captures nodule location(s) by name, laterality, size estimates, and any prior or current treatment (e.g., steroid injection, surgical excision) from the encounter narrative. It also pulls rheumatoid factor and anti-CCP status to pair M06.39 with the correct underlying RA code. This prevents the common error of collapsing a documented multi-site nodular complication into the nonspecific M06.9, which can trigger medical necessity denials for biologic therapy claims.

See how Mira captures M06.39 documentation

Related ICD-10 codes

Ready?

Ready to transform your orthopedic practice?

See how orthopedic practices are running documentation, billing, and operations on a single voice-first platform.

Get started for free