ICD-10-CM · Other

M86.08

Acute hematogenous osteomyelitis occurring at anatomical sites not captured by the more specific M86.0x codes — including the ilium, ischium, neck, ribs, and skull.

Verified May 8, 2026 · 6 sources ↓

Status: Billable
Chapter: 13
Related CPT: 14
Region: Other

Drawn from CDCICD10DataAAPCFindacodeCMS

Documentation tips

What should appear in the chart to support M86.08.

Source · Editorial brief grounded in 6 cited references ↓

Explicitly name the anatomical site (e.g., 'right ilium,' 'skull,' 'rib 6') — 'other sites' is a residual category, and the note must confirm the site does not belong in a more specific M86.0x code.
Document the mechanism as hematogenous (bloodstream-borne from a remote infection focus) to distinguish from direct inoculation osteomyelitis coded under M86.1x.
Record blood culture results or MRI findings (bone marrow edema on T2-weighted sequences) that support the acute diagnosis — these are the primary clinical validators for M86.0x codes.
Document the causative organism when identified (e.g., Staphylococcus aureus, Streptococcus) and assign the appropriate B95–B96 additional code to capture the pathogen.
Note any major osseous defect so M89.7- can be added as required by the Tabular use-additional-code instruction.
Confirm that vertebral involvement is absent; if the spine is affected, use M46.2- instead — M86.0x explicitly excludes vertebral osteomyelitis.

Related CPT procedures

Procedure codes commonly billed with M86.08. Linking the right diagnosis to the right procedure is what establishes medical necessity.

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

20240 $126.59

Open surgical biopsy of a superficial bone, such as the ilium, sternum, spinous process, rib, or femoral trochanter, performed through a skin incision to obtain tissue for diagnosis.

20245 $303.28

Surgical removal of a bone tissue sample from a deep anatomical site — such as the humeral shaft, ischium, or femoral shaft — through an open incision for pathological analysis.

27070 $826.00

Superficial partial excision of the wing of the ilium, symphysis pubis, or greater trochanter of the femur using craterization or saucerization technique, typically performed for osteomyelitis or bone abscess.

27071 $916.19

Deep partial excision of the iliac wing, symphysis pubis, or greater trochanter of the femur, including techniques such as craterization or saucerization.

23170 $540.76

Surgical removal of a sequestrum — a segment of necrotic bone — from the clavicle, typically performed to treat osteomyelitis or a bone abscess.

23172 $545.77

Surgical removal of a sequestrum (necrotic bone fragment) from the scapula, typically performed to treat chronic osteomyelitis or a bone abscess of the shoulder blade.

21025 $840.03

Surgical removal of infected or necrotic bone from the mandible, performed to treat osteomyelitis or bone abscess unresponsive to conservative management.

21026 $576.17

Surgical removal of infected or diseased bone tissue from one or more facial bones, typically performed for osteomyelitis or bone abscess that has not responded to antibiotic therapy.

72040 $39.75

Radiologic examination of the cervical spine capturing two or three views (e.g., AP, lateral, oblique).

99213 $95.19

Established patient office or outpatient visit requiring 20–29 minutes of total time or low-complexity medical decision-making.

99214 $135.61

Office visit for an established patient requiring moderate-complexity medical decision making (MDM), or 30–39 minutes of total provider time on the date of service.

99215 $192.39

Highest-level office or outpatient E/M visit for an established patient, qualifying via high-complexity medical decision making or 40–54 minutes of total provider time on the date of service.

70250 View procedure details

71046 View procedure details

Common coding pitfalls

The recurring mistakes coders make with M86.08 and adjacent codes.

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

Assigning M86.08 for vertebral osteomyelitis — vertebral involvement is an Excludes2 condition under M86 and must be coded to M46.2-, not M86.08.
Using M86.08 when the infection arose from an open wound, open fracture, or surgical procedure — that mechanism maps to M86.1x (other acute osteomyelitis), not M86.0x (hematogenous).
Confusing M86.08 with M86.8X8 (other osteomyelitis, other site) — M86.8 is a distinct subcategory covering Brodie's abscess and other unclassified forms, not acute hematogenous disease.
Selecting M86.09 (multiple sites) when only one 'other site' is affected — M86.09 requires documented infection at multiple anatomical locations simultaneously.
Failing to add a causative organism code (B95–B96) when the pathogen is identified, leaving clinically available specificity on the table and potentially affecting DRG severity tier.

Clinical context

Source · Editorial summary grounded in 6 cited references ↓

M86.08 is the correct billable code when acute hematogenous osteomyelitis is confirmed at a site that lacks its own dedicated 6th-character code in the M86.0 subcategory. The named 'other sites' explicitly covered by this code include the ilium, ischium, cervical/thoracic/lumbar neck structures outside the vertebral body, ribs, and skull. If the infection involves the vertebra, do not use M86.08 — vertebral osteomyelitis is excluded from M86 entirely and belongs in M46.2-.

Acute hematogenous osteomyelitis results from bacteremic seeding of bone from a remote infection source — not from direct inoculation or contiguous spread. Staphylococcus aureus is the predominant causative organism. The provider must document the acute onset and the hematogenous mechanism to distinguish this from M86.1x (other acute osteomyelitis, which covers direct inoculation) and from subacute (M86.2) or chronic (M86.3–M86.6) forms.

For MS-DRG assignment, M86.08 maps to MDC 08 under DRG 539/540/541 (Osteomyelitis with MCC/CC/without CC-MCC). The DRG tier reached depends entirely on documented comorbidities and complications, so thorough problem-list coding directly affects reimbursement. Use additional code M89.7- to capture any major osseous defect when present. If osteomyelitis is a complication of diabetes, link it explicitly to the diabetes code (e.g., E11.69) per sequencing guidelines.

Sibling codes

Other billable codes under M86.0 (laterality / anatomic variants).

M86.00

Acute hematogenous osteomyelitis, unspecified site

M86.09

Acute hematogenous osteomyelitis, multiple sites

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 6 cited references ↓

01Which specific anatomical sites are captured by M86.08?

The ICD-10-CM Tabular List index specifically routes ilium, ischium, neck (cervical structures outside the vertebral body), ribs, and skull to M86.08. Any other site not covered by M86.01 through M86.07 also maps here by convention.

02Can M86.08 be used for spinal osteomyelitis?

No. Vertebral osteomyelitis is excluded from the entire M86 category by an Excludes2 note. Use M46.2- (Osteomyelitis of vertebra) for spinal involvement, regardless of whether it is hematogenous in origin.

03What distinguishes M86.08 from M86.18 (other acute osteomyelitis, other sites)?

M86.08 requires a documented hematogenous mechanism — the infection spread via the bloodstream from a remote site. M86.18 covers acute osteomyelitis from direct inoculation (open fracture, wound, or surgical contamination). The mechanism must be stated or clearly inferable from the clinical note.

04Should a causative organism code always be added with M86.08?

Yes, when the organism is identified. The M86 category carries a use-additional-code instruction for organism identification. Assign B95.x for streptococcal or staphylococcal species, B96.x for other bacterial agents. This also supports accurate DRG severity classification.

05How does M86.08 affect DRG assignment?

M86.08 maps to MDC 08 under DRG 539 (with MCC), 540 (with CC), or 541 (without CC/MCC) per CMS MS-DRG v37.0. The tier depends on documented comorbidities — thorough secondary diagnosis coding directly determines which DRG is triggered.

06Is M86.08 valid for pediatric patients with hematogenous osteomyelitis of the pelvis?

Yes. Acute hematogenous osteomyelitis disproportionately affects children and adolescents, and pelvic bones (ilium, ischium) are recognized sites. M86.08 is appropriate when provider documentation confirms the acute hematogenous nature and identifies the pelvic site.

07When should M89.7- be added alongside M86.08?

Add M89.7- (major osseous defect) when imaging or intraoperative findings document significant bone loss or structural compromise at the infection site. The Tabular List includes a use-additional-code instruction for M89.7- across the M86 category.

Sources & references

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

01CDC ICD-10-CM Tabular List 2026 (FY2026, effective Oct 1, 2025)
02
icd10data.com
https://www.icd10data.com/ICD10CM/Codes/M00-M99/M86-M90/M86-/M86.08
03
aapc.com
https://www.aapc.com/codes/icd-10-codes/M86.08
04
findacode.com
https://www.findacode.com/news/icd10-osteomyelitis-documentation.html
05
cms.gov
https://www.cms.gov/icd10m/version37-fullcode-cms/fullcode_cms/P0211.html
06
icdcodes.ai
https://icdcodes.ai/diagnosis/osteomyelitis/documentation

Mira AI Scribe

The Mira AI Scribe captures the documented infection site by name (e.g., right ilium, rib, skull), the hematogenous mechanism or remote infection source, culture results with organism identification, and MRI or imaging findings consistent with acute bone marrow involvement. This prevents site ambiguity that would force a drop to M86.00 (unspecified site), a pathogen-code gap that suppresses DRG severity, or misrouting to M86.1x if mechanism isn't clearly recorded.

See how Mira captures M86.08 documentation