M71.10 classifies infective bursitis caused by a pathogen other than those captured by more specific codes, where the anatomical site of the affected bursa is not documented or cannot be determined.

Documentation tips

What should appear in the chart to support M71.10.

Source · Editorial brief grounded in 4 cited references ↓

• Name the causative organism in the assessment — document culture results or preliminary gram stain so a B95 or B96 code can be appended as required by the M71.1 Use Additional Code instruction.
• If the provider can identify the bursa location (e.g., olecranon, prepatellar, subdeltoid), document it explicitly — that moves the code to a site-specific M71.11–M71.19 child code, which is more specific and less audit-prone.
• Document onset, duration, and signs of infection (erythema, warmth, fluctuance, fever) to establish infectious etiology and distinguish from non-infective bursitis coded under M70.- or M71.9-.
• Record aspirate findings — cell count, organism, and Gram stain — to support the infective diagnosis and link laboratory results to the ICD-10 selection.
• Confirm that the unspecified site designation reflects a genuine documentation gap, not an oversight — payers may query claims where site-specific codes exist but the less-specific code was used.

Related CPT procedures

Procedure codes commonly billed with M71.10. 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 M71.10 and adjacent codes.

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

• Skipping the required B95/B96 secondary organism code: the M71.1 parent block explicitly requires 'Use Additional Code' to identify the causative organism whenever known — submitting M71.10 alone is incomplete.
• Using M71.10 when a site-specific code applies: if the provider documents 'right elbow' or 'left knee,' M71.10 is wrong — use M71.121 or the appropriate M71.1x child code instead.
• Confusing infective bursitis (M71.10) with non-infective/mechanical bursitis: overuse-related bursitis routes to M70.-, not M71.10, regardless of whether the bursa is inflamed.
• Billing M71.10 for septic bursitis when the site is documented in the procedure report (aspiration note) but not the diagnostic assessment — coders should cross-reference procedural notes for site documentation.
• Using the non-billable parent M71.1 instead of the specific M71.10 when site is truly unspecified — M71.1 alone will reject as a non-specific code.

Clinical context

Source · Editorial summary grounded in 4 cited references ↓

Sibling codes

Other billable codes under M71.1 (laterality / anatomic variants).