ICD-10-CM · Hand

M70.12

Inflammation of one or more bursae in the left hand, classified under soft tissue disorders related to use, overuse, and pressure.

Verified May 8, 2026 · 4 sources ↓

Status: Billable
Chapter: 13
Related CPT: 5
Region: Hand

Drawn from CDCICD10DataAAPCCMS

Documentation tips

What should appear in the chart to support M70.12.

Source · Editorial brief grounded in 4 cited references ↓

Explicitly document 'left hand' as the affected side — laterality is built into the 5th character and must be supported by the clinical note.
Record the occupational or repetitive-use history that links this bursitis to use, overuse, or pressure; this is required to stay within the M70 category rather than falling back to M71.9 (bursitis NOS).
Note the specific bursa or anatomic location within the hand (e.g., finger, metacarpal region) if identifiable — supports medical necessity and differentiates from wrist bursitis.
Document any imaging findings (ultrasound, MRI) confirming bursal distension or inflammation in the left hand.
If the etiology is occupational, capture the patient's job duties or activity. Append a Y93 external cause code to identify the causative activity when documented.

Related CPT procedures

Procedure codes commonly billed with M70.12. Linking the right diagnosis to the right procedure is what establishes medical necessity.

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

20600 $56.11

Needle aspiration and/or injection of a small joint or bursa — such as a finger or toe joint — performed without ultrasound guidance.

20604 $87.18

Arthrocentesis, aspiration and/or injection of a small joint or bursa (e.g., fingers, toes) performed with ultrasound guidance, including permanent image recording and reporting.

73130 $38.08

Radiographic examination of the hand requiring a minimum of three views.

26160 $657.66

Surgical excision of a tumor or cyst arising from a tendon sheath in the hand or finger, requiring complete removal of the lesion and its sheath attachment.

97012 View procedure details

Common coding pitfalls

The recurring mistakes coders make with M70.12 and adjacent codes.

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

Using M71.9 (bursitis NOS) instead of M70.12 when the bursitis has a clear occupational or repetitive-use etiology — M70.12 is the correct, more specific code in that scenario.
Assigning M70.12 for shoulder bursitis: the M70 category has a Type 2 Excludes for bursitis of shoulder (M75.5); those must be coded separately.
Coding only M70.12 for bilateral hand bursitis — bilateral is not a single code option under M70.1; you must report M70.11 and M70.12 together.
Dropping to the unspecified code M70.10 when the provider has documented 'left' — specificity is available and payers expect it.
Conflating hand bursitis with wrist bursitis: M70.1x covers the hand; wrist bursitis falls under M70.03x. Document the anatomic region precisely.

Clinical context

Source · Editorial summary grounded in 4 cited references ↓

M70.12 codes bursitis of the left hand when the condition is attributable to occupational or repetitive-use origin. The M70 category explicitly includes soft tissue disorders of occupational origin, so this code is the correct choice when the bursitis is linked to job duties, repetitive motion, or sustained pressure — not when the etiology is unknown or unspecified.

When laterality is documented as left, M70.12 is the specific billable code. If the provider documents bilateral hand bursitis, you will need separate codes: M70.11 (right) and M70.12 (left). If laterality is not documented at all, drop to M70.10 (unspecified hand). Do not use M70.12 for shoulder bursitis (M75.5), bursitis NOS with no occupational link (M71.9), or enthesopathies (M76–M77) — all are explicitly excluded from the M70 category.

M70.12 supports medical necessity for bursal injection procedures per CMS Draft Article DA52863. Use an additional external cause code from Y93 to identify the activity causing the disorder when that information is documented. This code groups to MS-DRG 557 (Tendonitis, myositis and bursitis with MCC) or 558 (without MCC) under MS-DRG v42.0.

Sibling codes

Other billable codes under M70.1 (laterality / anatomic variants).

M70.11

Bursitis, right hand

M70.10

Bursitis, unspecified hand

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 4 cited references ↓

01When should I use M70.12 instead of M71.9?

Use M70.12 when the bursitis is linked to use, overuse, or occupational pressure on the left hand. M71.9 (bursitis NOS) is correct only when there is no documented activity-related or occupational etiology — and M70.12 excludes M71.9 per the category-level Type 1 Excludes note.

02Is there a single code for bilateral hand bursitis?

No. The M70.1 subcategory has no bilateral option. Report M70.11 (right) and M70.12 (left) together when both hands are affected and each side is documented.

03Can M70.12 be used for bursitis caused by a single traumatic event?

The M70 category covers disorders related to use, overuse, and pressure — not acute trauma. If bursitis is explicitly attributed to a single traumatic incident, consider an appropriate injury code and flag for payer-specific guidance, as some payers accept M70.12 for post-traumatic presentations while others require an S-code.

04Do I need an external cause code with M70.12?

Yes, when the causative activity is documented. The M70 category instructs 'Use additional external cause code to identify activity causing disorder (Y93.-)'. Append the appropriate Y93 code to strengthen medical necessity documentation.

05What CPT procedure codes pair with M70.12 for bursal injections?

CMS Draft Article DA52863 lists M70.12 as a supporting diagnosis for bursal injection procedures. CPT 20600 (aspiration and/or injection, small joint or bursa) is commonly paired; confirm with the payer's LCD for specific procedure-to-diagnosis linkage requirements.

06What MS-DRGs does M70.12 map to?

Under MS-DRG v42.0, M70.12 groups to DRG 557 (Tendonitis, myositis and bursitis with MCC) or DRG 558 (without MCC), depending on the presence of major complicating or comorbid conditions documented in the encounter.

07Is M70.12 valid for FY2026?

Yes. M70.12 has been a valid, billable ICD-10-CM code since FY2016 and carries forward unchanged into FY2026 (effective October 1, 2025) per the CDC ICD-10-CM Tabular List 2026.

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/M70-/M70.12
03
aapc.com
https://www.aapc.com/codes/icd-10-codes/M70.12
04
cms.gov
https://www.cms.gov/medicare-coverage-database/view/article.aspx?articleId=60304&ver=3

Mira AI Scribe

Mira's AI scribe captures documented laterality (left), occupational or repetitive-use history, specific anatomic location within the hand, and any imaging confirmation of bursal inflammation. Accurate capture of these elements locks in M70.12 over the unspecified M70.10, prevents a fallback to the less specific M71.9, and satisfies CMS medical-necessity requirements for bursal injection coding.

See how Mira captures M70.12 documentation