ICD-10-CM · Multi-region

M85.69

Other cyst of bone affecting multiple anatomical sites simultaneously, not classifiable to a single skeletal location.

Verified May 8, 2026 · 4 sources ↓

Status
Billable
Chapter
13
Related CPT
9
Region
Multi-region
Drawn from CDCICD10DataClassbrowser

Documentation tips

What should appear in the chart to support M85.69.

Source · Editorial brief grounded in 4 cited references ↓

  • Name every distinct skeletal site involved — 'multiple bone cysts' alone is insufficient; list each bone by name and laterality.
  • Reference the imaging modality (X-ray, MRI, CT, bone scan) and findings at each site that confirm cystic morphology (fluid-filled cavity, sclerotic border, no soft tissue mass).
  • Distinguish the cyst type in the note: simple/unicameral, intraosseous ganglion, or 'other' — this supports M85.6x over M85.5 (aneurysmal) and M85.0x (fibrous dysplasia).
  • Document that jaw cysts are absent or code jaw cysts separately under K09.2 — the Tabular List explicitly excludes jaw from M85.6x.
  • Record prior treatment history (aspiration, steroid injection, curettage) per site if applicable, as this establishes medical necessity for repeat imaging or intervention.

Related CPT procedures

Procedure codes commonly billed with M85.69. 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 M85.69 and adjacent codes.

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

  • Using M85.69 when cysts are bilateral at a single joint (e.g., both distal femora) — bilateral involvement of one region does not equal multiple sites; use the site-specific unspecified-laterality code instead.
  • Conflating M85.69 with M85.68 (other site, singular) when only one non-listed anatomical site is involved — M85.69 requires explicit documentation of more than one skeletal site.
  • Failing to exclude aneurysmal bone cyst (M85.5) before assigning M85.69 — aneurysmal cysts have a distinct code regardless of site count.
  • Coding jaw cysts under M85.69 when K09.2 is required per the ICD-10-CM tabular exclusion note.
  • Defaulting to M85.69 when site is simply unspecified — use M85.60 (unspecified site) if the record lacks site detail, not the multiple-sites code.

Clinical context

Source · Editorial summary grounded in 4 cited references ↓

M85.69 is the correct code when a patient presents with non-aneurysmal, non-solitary bone cysts documented at more than one distinct skeletal site. This includes simple (unicameral) bone cysts and other benign osseous cysts that don't fit the more specific subcategories under M85.6 — such as aneurysmal bone cyst (M85.5) or fibrous dysplasia (M85.0). The multiple-site qualifier is what separates M85.69 from M85.68 (other single site) and the site-specific bilateral or unilateral codes within M85.60–M85.67.

Common clinical scenarios include incidental findings on skeletal survey showing cystic lesions at two or more bones, or a patient with a known systemic skeletal condition (e.g., fibrous dysplasia excluded by coding rules) who has documented cysts spanning different anatomical regions. Bone cysts captured here are distinct from jaw cysts (K09.2) and from cysts that meet criteria for neoplastic or metabolic etiologies coded elsewhere.

Do not use M85.69 when cysts are limited to a single anatomical region — even bilaterally — unless the documentation explicitly describes involvement of multiple distinct skeletal sites. If documentation names only one site, use the appropriate site-specific child code under M85.60–M85.68. Reserve M85.69 for genuinely multi-site involvement as confirmed by imaging or operative findings.

Sibling codes

Other billable codes under M85.6 (laterality / anatomic variants).

Frequently asked questions

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

01What distinguishes M85.69 from M85.68?
M85.68 applies when one bone cyst exists at a site not listed in M85.61–M85.67. M85.69 requires two or more distinct skeletal sites. If only one site is involved — even an unusual one — use M85.68.
02Can I use M85.69 for bilateral bone cysts at the same anatomical region?
No. Bilateral cysts confined to a single anatomical region (e.g., both proximal humeri) should be coded to the site-specific unspecified-laterality child code (e.g., M85.629), not M85.69. Multiple sites means multiple distinct skeletal regions.
03Should aneurysmal bone cysts at multiple sites be coded M85.69?
No. Aneurysmal bone cyst has its own category: M85.5x with site-specific subcode. M85.69 is for 'other' cysts of bone — non-aneurysmal types. Assign M85.57 or M85.58/M85.59 as appropriate for aneurysmal cysts.
04What imaging documentation supports M85.69 for audit purposes?
Radiology reports naming each affected bone with descriptors consistent with a benign cyst (well-defined margins, fluid attenuation, no aggressive periosteal reaction) at two or more sites. MRI, CT, or plain film reports all qualify — the key is site-specific confirmation.
05Is M85.69 used when a jaw cyst is one of the multiple sites?
No. Jaw cysts are explicitly excluded from M85.6x per the ICD-10-CM Tabular List; they code to K09.2. If the patient has a jaw cyst plus a bone cyst elsewhere, code K09.2 separately and use the appropriate single-site M85.6x code for the non-jaw cyst.
06Does M85.69 require a 7th character extension?
No. M85.69 is a fully specified 5-character billable code under Chapter 13 (M-codes). Seventh-character extensions (A, D, S) apply to injury codes (S-codes), not to musculoskeletal disease codes like M85.69.

Sources & references

Editorial content was developed using the following public sources. Last verified May 8, 2026.

  1. 01CDC ICD-10-CM Tabular List 2026 (FY2026, effective October 1, 2025)
  2. 02
    icd10data.com
    https://www.icd10data.com/ICD10CM/Codes/M00-M99/M80-M85/M85-/M85.69
  3. 03
    icd10data.com
    https://www.icd10data.com/ICD10CM/Codes/M00-M99/M80-M85/M85-
  4. 04
    classbrowser.nhs.uk
    https://classbrowser.nhs.uk/ref_books/ICD-10_2025_5th_Ed_NCCS.pdf

Mira AI Scribe

Mira AI Scribe captures the name and laterality of each bone site with documented cystic lesions, the imaging modality and key findings (fluid signal, sclerotic margins, no periosteal reaction), cyst type characterization, and any prior treatment per site. This prevents assignment of the single-site or unspecified-site codes (M85.68, M85.60) when multi-site involvement is the clinical reality — avoiding a specificity downgrade that can trigger payer documentation requests.

See how Mira captures M85.69 documentation

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