M86.4 – Chronic osteomyelitis with draining sinus

ICD-10-CM 2027 diagnosis code · Other osteopathies

Non-billable header

ICD-10-CM code M86.4

Code: M86.4 (claims format: M864)
Description: Chronic osteomyelitis with draining sinus
Billable: No – use a more specific code below
Valid for: Dates of service October 1, 2026 – September 30, 2027 (FY2027)
Chapter: 13. Diseases of the musculoskeletal system and connective tissue (M00-M99)
Block: M86-M90 Other osteopathies
Parent codes: M86

Billable codes under M86.4

M86.4 is a header code and cannot be used on claims. Choose the most specific code:

M86.40 – Chronic osteomyelitis with draining sinus, unspecified siteBillable
M86.41 – Chronic osteomyelitis with draining sinus, shoulderHeader (more codes below)
M86.42 – Chronic osteomyelitis with draining sinus, humerusHeader (more codes below)
M86.43 – Chronic osteomyelitis with draining sinus, radius and ulnaHeader (more codes below)
M86.44 – Chronic osteomyelitis with draining sinus, handHeader (more codes below)
M86.45 – Chronic osteomyelitis with draining sinus, femurHeader (more codes below)
M86.46 – Chronic osteomyelitis with draining sinus, tibia and fibulaHeader (more codes below)
M86.47 – Chronic osteomyelitis with draining sinus, ankle and footHeader (more codes below)
M86.48 – Chronic osteomyelitis with draining sinus, other siteBillable
M86.49 – Chronic osteomyelitis with draining sinus, multiple sitesBillable

Notes inherited from parent codes

Instructional notes at a category or block level apply to every code below it.

M86 – Osteomyelitis

Excludes1 (not coded here):

osteomyelitis due to:
echinococcus (B67.2)
gonococcus (A54.43)
salmonella (A02.24)

Excludes2 (not included here):

ostemyelitis of:
orbit (H05.0-)
petrous bone (H70.2-)
vertebra (M46.2-)

Use additional code:

code (B95-B97) to identify infectious agent
code to identify major osseous defect, if applicable (M89.7-)

Block M86-M90

Excludes1 (not coded here):

postprocedural osteopathies (M96.-)

Related codes in M86

M86.0 – Acute hematogenous osteomyelitisHeader
M86.1 – Other acute osteomyelitisHeader
M86.2 – Subacute osteomyelitisHeader
M86.3 – Chronic multifocal osteomyelitisHeader
M86.5 – Other chronic hematogenous osteomyelitisHeader
M86.6 – Other chronic osteomyelitisHeader
M86.8 – Other osteomyelitisHeader
M86.9 – Osteomyelitis, unspecifiedBillable

Frequently asked questions

What is ICD-10 code M86.4?

M86.4 is the ICD-10-CM code for chronic osteomyelitis with draining sinus, in the block M86-M90 (Other osteopathies).

Is M86.4 a billable code?

No. M86.4 is a header code with more specific child codes; report one of the billable codes listed above.

What category does M86.4 belong to?

It belongs to category M86 – Osteomyelitis.

Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.