M67.98 captures an unspecified disorder of the synovium or tendon at a site that does not map to the more precisely defined anatomical locations in the M67 subcategory — used when the affected structure is documented but the specific diagnosis within the synovium/tendon category cannot be determined.
Verified May 8, 2026 · 5 sources ↓
- Status
- Billable
- Chapter
- 13
- Related CPT
- 10
- Region
- Other
Documentation tips
What should appear in the chart to support M67.98.
Source · Editorial brief grounded in 5 cited references ↓
- Name the exact anatomical site (e.g., 'chest wall tendon,' 'trunk synovium') — 'other site' requires the note to confirm the site falls outside shoulder, elbow, wrist, hand, hip, knee, and ankle/foot.
- Document why a more specific M67 subcategory (synovial hypertrophy, ganglion, plica, contracture) does not apply — this justifies the 'unspecified' designation and reduces audit risk.
- Record all imaging findings (ultrasound, MRI) with the radiologist's impression; if imaging is pending, note that the diagnosis is working/provisional pending results.
- Confirm and document the absence of tendinitis NOS (M77.9-), Dupuytren's contracture (M72.0), and tendon xanthomatosis (E78.2) to satisfy the M67 Excludes1 requirements.
- If the disorder later resolves to a specific diagnosis, update the code on subsequent visits — using M67.98 as a permanent code when specificity is achievable is an audit flag.
Related CPT procedures
Procedure codes commonly billed with M67.98. 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 M67.98 and adjacent codes.
Source · Editorial brief grounded in CDC ICD-10-CM tabular guidance, AAOS coding references, and cited references ↓
- Assigning M67.98 when tendinitis NOS is the actual diagnosis — tendinitis NOS codes to M77.9-, which is an Excludes1 condition at the M67 level and cannot coexist with M67.98.
- Defaulting to M67.98 for common sites like knee or shoulder when laterality-specific unspecified codes (e.g., M67.961 right knee, M67.962 left knee) exist and should be used instead.
- Using M67.98 when a specific synovial/tendon condition — ganglion (M67.4x), plica (M67.5x), or synovial hypertrophy (M67.2x) — is clearly documented, bypassing more precise codes.
- Omitting supporting documentation that explains why the 'other site' designation applies; without it, the claim looks like a coding shortcut rather than a clinically justified choice.
Clinical context
Source · Editorial summary grounded in 5 cited references ↓
M67.98 sits at the bottom of the M67.9x unspecified cluster and is reserved for synovial or tendon pathology at anatomical sites not covered by the laterality-specific codes in M67.90–M67.979 (e.g., unspecified site, shoulder, elbow, wrist, hand, hip, thigh, knee, ankle/foot, and bilateral variants). The 'other site' designation in M67.98 applies when the affected structure falls outside those enumerated locations — for example, the chest wall, thorax, or trunk — and the clinician cannot narrow the diagnosis to a more specific M67 subcategory such as synovial hypertrophy (M67.2x), ganglion (M67.4x), or plica (M67.5x).
Before assigning M67.98, exhaust site-specific and condition-specific codes. Tendinitis NOS maps to M77.9-, not M67.98; Dupuytren's contracture maps to M72.0; and xanthomatosis localized to tendons maps to E78.2 — all three are Excludes1 exclusions at the M67 category level, meaning they cannot be coded alongside M67.98. If a more definitive diagnosis exists (synovitis, tenosynovitis, rupture, contracture, plica syndrome), code the specific condition instead.
M67.98 is a billable code appropriate for reimbursement, but payers scrutinize unspecified codes for medical necessity. Use it as a working diagnosis when diagnostic workup is ongoing, or as a permanent code only when the clinical record genuinely cannot support greater specificity. Pair with procedure codes for imaging or aspiration that are driving the visit to strengthen medical necessity on the claim.
Sibling codes
Other billable codes under M67.9 (laterality / anatomic variants).
Frequently asked questions
Source · Generated from the editorial pipeline, verified against 5 cited references ↓
01What does 'other site' mean in M67.98?
02Can I use M67.98 for tendinitis?
03Is M67.98 appropriate as a permanent diagnosis code, or only a working diagnosis?
04What is the difference between M67.98 and M67.99?
05What Excludes1 conditions must I rule out before using M67.98?
06Which CPT procedures most commonly pair with M67.98?
07Will payers deny M67.98 as too unspecified?
Sources & references
Editorial content was developed using the following public sources. Last verified May 8, 2026.
- 01CDC ICD-10-CM Tabular List 2026 (FY2026, effective Oct 1, 2025)
- 02icd10data.comhttps://www.icd10data.com/ICD10CM/Codes/M00-M99/M65-M67/M67-/M67.98
- 03aapc.comhttps://www.aapc.com/codes/icd-10-codes/M67.98
- 04aapc.comhttps://www.aapc.com/codes/icd-10-codes/M67.9
- 05icdcodes.aihttps://icdcodes.ai/diagnosis/tendonitis/documentation
Mira AI Scribe
Mira's AI scribe captures the anatomical site name, the clinician's description of the synovial or tendon abnormality, relevant imaging impressions, and any exclusion of more specific diagnoses (tendinitis, ganglion, plica, contracture). That documentation prevents downcoding to a non-billable unspecified parent code and gives the payer the site justification needed to defend the 'other site' designation on audit.
See how Mira captures M67.98 documentation