M77.22 identifies periarthritis of the left wrist — inflammation of the soft tissues surrounding the wrist joint, including tendons, tendon sheaths, and periarticular structures, without primary intra-articular pathology.
Verified May 8, 2026 · 5 sources ↓
- Status
- Billable
- Chapter
- 13
- Related CPT
- 5
- Region
- Wrist
Documentation tips
What should appear in the chart to support M77.22.
Source · Editorial brief grounded in 5 cited references ↓
- Explicitly document 'left wrist' laterality — without it, the coder must drop to M77.20 (unspecified), which risks downcoding and payer edit flags.
- Record the clinical basis for a periarticular vs. intra-articular diagnosis: tenderness at tendon insertion sites, preserved joint space on imaging, or negative synovitis workup all support M77.22 over an arthritis code.
- If an injection is performed, document the anatomical target (tendon sheath vs. joint vs. bursa) — this determines whether CPT 20550, 20600, or another procedure code applies, and whether M77.22 is the correct primary diagnosis.
- Note any external cause if the periarthritis is work-related or activity-related; an external cause code should follow M77.22 per Chapter 13 guidelines.
- Document conservative care history (physical therapy, NSAIDs, splinting) if the visit supports medical necessity for a procedure or specialist referral.
Related CPT procedures
Procedure codes commonly billed with M77.22. 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 M77.22 and adjacent codes.
Source · Editorial brief grounded in CDC ICD-10-CM tabular guidance, AAOS coding references, and cited references ↓
- Coding M77.22 alongside M71.9 (bursitis NOS) violates the Excludes1 note at M77 — choose the code that best matches the documented diagnosis, not both.
- Defaulting to M77.20 (unspecified wrist) when the note clearly states 'left' — always assign the laterality-specific code when documented.
- Confusing periarthritis with de Quervain tenosynovitis (M65.4) or other specific tenosynovitis (M65.8-): if the provider has documented a named tendon-sheath condition, use the more specific code rather than M77.22.
- Using M77.22 for bilateral wrist periarthritis without also coding the right side — there is no bilateral code in M77.2, so code M77.21 and M77.22 together when both wrists are documented.
Clinical context
Source · Editorial summary grounded in 5 cited references ↓
M77.22 is the billable code for left wrist periarthritis under category M77.2 (Periarthritis of wrist), itself nested within M77 (Other enthesopathies) in the soft tissue disorders section (M60–M79). Use it when the provider documents diffuse periarticular pain, stiffness, or inflammation localized to the left wrist and attributes it to a soft tissue or enthesopathic process rather than synovitis, bursitis, or intra-articular arthritis.
This code groups into MS-DRG 557 (Tendonitis, myositis and bursitis with MCC) or 558 (without MCC), so documentation of comorbidity burden directly affects DRG assignment. If the encounter involves a tendon sheath injection (CPT 20550) or a joint/bursa injection (CPT 20600), confirm the clinical diagnosis matches M77.22 rather than a more specific code such as M65.4 (de Quervain tenosynovitis) or M65.8x (other tenosynovitis), which describe distinct pathologies.
Key exclusions at the M77 category level: do not use M77.22 when bursitis NOS (M71.9) is the documented diagnosis — that is an Excludes1 conflict, meaning the two codes cannot coexist. Bursitis due to use, overuse, or pressure (M70.-), osteophyte (M25.7), and spinal enthesopathy (M46.0-) are Excludes2 conditions, meaning they may be coded separately if both are genuinely present and documented.
Sibling codes
Other billable codes under M77.2 (laterality / anatomic variants).
Frequently asked questions
Source · Generated from the editorial pipeline, verified against 5 cited references ↓
01What is the difference between M77.22 and M77.20?
02Can M77.22 and M71.9 (bursitis NOS) be coded together?
03Is there a bilateral wrist periarthritis code?
04Which CPT codes most commonly pair with M77.22 in an orthopedic practice?
05Does M77.22 require a 7th character extension?
06What MS-DRG does M77.22 map to for inpatient claims?
07Can M77.22 be coded alongside a de Quervain tenosynovitis code (M65.4)?
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/M70-M79/M77-/M77.22
- 03aapc.comhttps://www.aapc.com/codes/icd-10-codes/M77.22
- 04aapc.comhttps://www.aapc.com/codes/icd-10-codes/M77.2
- 05ecgwaves.comhttps://ecgwaves.com/icd-code/m77-22-periarthritis-left-wrist-icd-10-code-in-m60-m79-soft-tissue-disorders/
Mira AI Scribe
The Mira AI Scribe captures left-side laterality, the periarticular location of pain or tenderness (distinguishing it from intra-articular pathology), any imaging findings supporting soft tissue vs. joint-space involvement, and prior conservative treatment attempts. This prevents the coder from falling back to unspecified M77.20, avoids Excludes1 conflicts with bursitis codes, and ensures the injection procedure code — if applicable — is paired with the correct diagnosis.
See how Mira captures M77.22 documentation