Inflammation of the synovial lining of joints or tendon sheaths occurring at more than one anatomical site, where the condition does not fit a more specific M65 subcategory.
Verified May 8, 2026 · 5 sources ↓
- Status
- Billable
- Chapter
- 13
- Related CPT
- 15
- Region
- Multi-region
Documentation tips
What should appear in the chart to support M65.89.
Source · Editorial brief grounded in 5 cited references ↓
- Name every affected site explicitly (e.g., 'right wrist tenosynovitis and left ankle synovitis') — 'multiple joints' alone is insufficient to justify M65.89 over a single site-specific code.
- Specify that the condition is non-infectious; if an organism is identified, infectious tenosynovitis codes (M65.0–M65.1) take precedence and M65.89 is excluded.
- Record imaging findings (ultrasound or MRI) showing synovial thickening, effusion, or tendon sheath fluid at each affected site to support medical necessity across all locations.
- Document that overuse or pressure is not the primary etiology; if it is, M70-series codes apply and M65 is excluded by the Type 1 Excludes note.
- Capture chronicity and prior conservative treatment at each site — payors frequently require evidence that conservative measures were attempted before approving injections or advanced imaging at multiple locations.
Related CPT procedures
Procedure codes commonly billed with M65.89. 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 M65.89 and adjacent codes.
Source · Editorial brief grounded in CDC ICD-10-CM tabular guidance, AAOS coding references, and cited references ↓
- Assigning M65.89 when only one site is affected — use the appropriate single-site M65.8x code instead (e.g., M65.811 for right shoulder).
- Ignoring the Type 1 Excludes at M65: coding M65.89 alongside any M70 code (overuse/pressure soft tissue disorders) on the same claim is incorrect.
- Using M65.89 for infectious tenosynovitis at multiple sites — infectious cases require M65.00–M65.19, not M65.89.
- Defaulting to M65.89 when a named condition such as trigger finger (M65.3) or de Quervain disease (M65.4) is documented — those codes are specific and must be used instead.
- Failing to verify that the parent code M65.8 (non-billable) is not submitted in place of the billable child code M65.89 — M65.8 alone will reject as non-specific.
Clinical context
Source · Editorial summary grounded in 5 cited references ↓
M65.89 applies when a patient presents with synovitis, tenosynovitis, or both affecting multiple body sites simultaneously — for example, concurrent wrist tenosynovitis and ankle synovitis — and the condition is not infectious (M65.0–M65.1), not abscess of tendon sheath (M65.0), not trigger finger (M65.3), and not de Quervain disease (M65.4). The '8' in M65.8 signals 'other' synovitis and tenosynovitis, meaning it captures presentations that don't map to named or site-specific subcategories already defined in the M65 hierarchy.
Before assigning M65.89, exhaust more specific options. M65.8 has site-specific child codes (shoulder, upper arm, forearm, hand, thigh, lower leg, ankle/foot, and other). Use M65.89 only when two or more of those distinct sites are simultaneously affected and a single site-specific code cannot represent the full clinical picture. If only one site is involved, drop to the appropriate site-specific M65.8x code.
Type 1 Excludes at the M65 category level bars simultaneous use with M70 codes (soft tissue disorders related to use, overuse, and pressure) and crepitant synovitis of the hand/wrist (M70.0). Confirm that the documented etiology is not overuse- or pressure-related before assigning M65.89. This code groups to MS-DRG 557 (Tendonitis, myositis and bursitis with MCC) or 558 (without MCC) under MS-DRG v43.0.
Sibling codes
Other billable codes under M65.8 (laterality / anatomic variants).
Frequently asked questions
Source · Generated from the editorial pipeline, verified against 5 cited references ↓
01When does M65.89 apply instead of a single-site M65.8x code?
02Can M65.89 and an M70 code be billed together?
03Does M65.89 require a 7th-character extension?
04What MS-DRGs does M65.89 map to?
05Can M65.89 be used for infectious tenosynovitis at multiple sites?
06Is M65.8 (the parent code) billable if multiple sites are involved?
07What imaging best supports M65.89 at multiple sites?
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/M65-M67/M65-/M65.89
- 03aapc.comhttps://www.aapc.com/codes/icd-10-codes/M65.89
- 04aapc.comhttps://www.aapc.com/codes/icd-10-codes/M65.8
- 05icd10data.comhttps://www.icd10data.com/ICD10CM/Codes/M00-M99/M65-M67/M65-
Mira Scribe
The Mira AI Scribe captures laterality and anatomical site for each affected joint or tendon sheath, imaging findings (ultrasound or MRI) at each location, infectious vs. non-infectious etiology, and prior conservative treatment history. That detail prevents downcoding to unspecified M67.90, blocks a Type 1 Excludes conflict with M70 codes, and satisfies multi-site medical necessity review.
See how Mira captures M65.89 documentation