M71.39 identifies non-synovial bursal cysts affecting two or more anatomically distinct sites simultaneously, classified under other bursopathies in the soft tissue disorders section.

Documentation tips

What should appear in the chart to support M71.39.

Source · Editorial brief grounded in 5 cited references ↓

• Name every affected anatomical site explicitly — 'bilateral elbow and right knee bursal cysts' — so multiple-site involvement is unambiguous and supports M71.39 over a single-site code.
• Specify the imaging modality and findings (e.g., MRI or ultrasound demonstrating discrete bursal cyst at each site) to validate the diagnosis and withstand audit scrutiny.
• Distinguish cyst from bursitis in the clinical note; a fluid-filled bursal cyst is not synonymous with inflammatory bursitis and maps to a different subcategory.
• Document whether the cysts are symptomatic at each site — pain, restricted motion, palpable mass — to support medical necessity for any injection or aspiration procedures billed.
• Note any associated systemic conditions (e.g., rheumatoid arthritis, gout) with separate codes, as these may explain multi-site bursal cyst formation and strengthen medical necessity.

Related CPT procedures

Procedure codes commonly billed with M71.39. 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 M71.39 and adjacent codes.

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

• Assigning M71.39 when only one site is documented — if the record supports a single location, use the site-specific M71.31–M71.38 code instead.
• Confusing bursal cysts (M71.3-) with Baker's cysts (M71.2-); Baker's cysts have their own subcategory and should not default to M71.39 even when bilateral.
• Using M71.39 for bursitis rather than bursal cyst — inflammatory bursitis at multiple sites maps to M71.59 (other bursitis, not elsewhere classified, multiple sites), not M71.39.
• Overlooking the Excludes1 note: synovial cyst with rupture (M66.1-) cannot be coded with M71.3-; if rupture is documented, M66.1- takes precedence.
• Defaulting to M71.39 when overuse or pressure is the documented etiology — those cases belong in the M70 category, not M71.

Clinical context

Source · Editorial summary grounded in 5 cited references ↓

Sibling codes

Other billable codes under M71.3 (laterality / anatomic variants).