M71.9

Bursopathy, unspecified captures bursal inflammation or disorder when the affected joint site is not documented or cannot be determined — the catch-all within the M71 Other Bursopathies category.

Verified May 8, 2026 · 5 sources ↓

Status: Billable
Chapter: 13
Related CPT: 6
Region: General

Drawn from CDCICD10DataAAPCCMSMS

Documentation tips

What should appear in the chart to support M71.9.

Source · Editorial brief grounded in 5 cited references ↓

Record the exact anatomic site of bursal tenderness or swelling by name (e.g., olecranon, prepatellar, trochanteric, subdeltoid) — any named site unlocks a more specific M71 subcode.
Document laterality explicitly (right vs. left); 'unspecified' laterality triggers additional scrutiny from payers even when a site-specific M71 code is used.
If you cannot name the site, explain why — e.g., 'diffuse bursal involvement, multiple sites' or 'site not yet confirmed pending imaging' — to justify M71.9 and satisfy audit requirements.
Note imaging findings (ultrasound or MRI confirmation of bursal fluid, wall thickening, or calcification) to support medical necessity for injections or aspiration billed alongside this code.
Document the treatment plan — NSAIDs, corticosteroid injection, aspiration, physical therapy — to substantiate the encounter and reduce denial risk on M71.9 claims.

Related CPT procedures

Procedure codes commonly billed with M71.9. Linking the right diagnosis to the right procedure is what establishes medical necessity.

Source · CMS LCDs · AAOS specialty guidance · claims-pattern analysis

20610 $68.81

Aspiration and/or injection of a major joint or bursa (shoulder, hip, knee, or subacromial bursa) performed without ultrasound guidance.

20611 $104.21

Aspiration or injection of a major joint or bursa performed under real-time ultrasound guidance, with permanent image documentation.

73221 $205.08

MRI of any upper extremity joint — shoulder, elbow, or wrist — performed without contrast material.

73721 $204.41

MRI of a lower extremity joint (hip, knee, or ankle) performed without contrast material.

27301 $720.12

Incision and drainage of a deep abscess, hematoma, or bursa located within the thigh or knee region, requiring dissection through subcutaneous tissue into fascia or muscle.

23931 $323.99

Incision and drainage of an infected or inflamed bursa located in the upper arm or elbow region.

Common coding pitfalls

The recurring mistakes coders make with M71.9 and adjacent codes.

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

Using M71.9 when the site is actually documented: if the note says 'trochanteric bursitis, left hip,' code M71.552, not M71.9.
Confusing M71.9 with M70.– codes: bursitis caused by repetitive use or occupational pressure belongs in M70.–, which is excluded from M71 by a Type 1 Excludes note.
Skipping site-specific M71 subcategories: calcium deposits in a bursa have their own M71.4x codes; defaulting to M71.9 misrepresents the pathology and may affect DRG assignment.
Reporting M71.9 alongside enthesopathy codes (M76–M77) for the same site without understanding the Type 1 Excludes hierarchy — those conditions are not coded together from M71.
Billing M71.9 repeatedly across encounters without an updated clinical rationale; payers interpret persistent 'unspecified' coding as incomplete documentation rather than a genuinely indeterminate diagnosis.

Clinical context

Source · Editorial summary grounded in 5 cited references ↓

M71.9 is the last-resort code in the M71 family. Use it only when the documentation fails to identify the anatomic site of the bursopathy or when the provider explicitly notes the site is indeterminate. If the affected joint is documented — shoulder, elbow, hip, knee, ankle — a site-specific M71 code with full laterality is required instead. The Tabular List also recognizes M71.9 as the home for 'Bursitis NOS,' so any encounter note that says simply 'bursitis' without further specificity maps here.

Before landing on M71.9, exhaust the M71 subcategories: M71.0x for bursal abscess, M71.1x for other infective bursitis, M71.2 for synovial cyst of popliteal space, M71.3x for other bursal cyst, M71.4x for calcium deposit in bursa, and M71.5x for other bursitis not elsewhere classified. Also review M70.– (bursitis related to use, overuse, or pressure) — that category has a Type 1 Excludes at the M71 level, meaning those codes are mutually exclusive. Enthesopathies (M76–M77) and bunion (M20.1) are likewise excluded from M71.

M71.9 groups into MS-DRG 557 (Tendonitis, Myositis and Bursitis with MCC) or 558 (without MCC). Payers increasingly flag unspecified codes for additional documentation; expect a request for records when M71.9 appears without supporting notes explaining why a site-specific code wasn't used.

Inclusion & exclusion notes

Per the official ICD-10-CM Tabular List.

Source · CDC ICD-10-CM Official Tabular List · 2026

Includes

Bursitis NOS

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 5 cited references ↓

01When is M71.9 appropriate versus a more specific M71 code?

M71.9 is appropriate only when the provider cannot document or determine the anatomic site of the bursopathy. If any named site is documented — shoulder, elbow, hip, knee, ankle, wrist — assign the corresponding site-specific M71 subcode with laterality.

02Does M71.9 require a modifier for laterality?

No CPT modifier is needed for laterality on the diagnosis side, but the absence of laterality in the code itself (M71.9 has no site or side) is exactly why payers scrutinize it. Make sure the procedure CPT code and operative notes reflect laterality where applicable.

03Can M71.9 be used when the patient has bursitis in multiple joints?

If multiple distinct sites are involved and each is documented, code each site-specific M71 code separately. M71.9 is not a substitute for multi-site coding; use it only when the exact sites genuinely cannot be determined.

04Is M71.9 accepted by Medicare and commercial payers for injection procedures like 20610?

M71.9 is billable and will process, but many payers flag unspecified codes for post-payment review. Expect higher denial or documentation-request rates compared to site-specific codes. Payer LCDs for joint injections often prefer or require a specific diagnosis code.

05What is the difference between M71.9 and M70.– bursitis codes?

M70.– covers bursitis directly caused by repetitive use, overuse, or prolonged pressure on a specific joint. A Type 1 Excludes at the M71 category level means M71.9 and M70.– codes cannot be used together for the same condition — if overuse is the cause, M70.– is the correct category.

06What MS-DRG does M71.9 map to for inpatient billing?

M71.9 groups to MS-DRG 557 (Tendonitis, Myositis and Bursitis with MCC) or MS-DRG 558 (without MCC), per MS-DRG v43.0. The MCC present on the claim determines which DRG applies.

07Should M71.9 ever appear as a secondary diagnosis?

Yes — for example, when a patient undergoing surgery for a primary orthopedic condition also has an unrelated, unspecified bursopathy being monitored. Code it as secondary only if it affects patient management during the encounter.

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)
02
icd10data.com
https://www.icd10data.com/ICD10CM/Codes/M00-M99/M70-M79/M71-/M71.9
03
aapc.com
https://www.aapc.com/codes/icd-10-codes/M71.9
04
cms.gov
https://www.cms.gov/medicare/coding/icd10/downloads/icd10clinicalconceptsorthopedics1.pdf
05MS-DRG v43.0 Grouper Documentation

Mira AI Scribe

Mira AI Scribe captures the anatomic site, laterality, symptom onset, aggravating factors, physical exam findings (point tenderness, swelling, range-of-motion limitation), and imaging results from the encounter note — all the data points that push the code from M71.9 to a site-specific M71 subcode. Locking those details at the point of care prevents downcoding, blocks unspecified-code audit flags, and eliminates payer record requests before they start.

See how Mira captures M71.9 documentation