M86.422 Chronic osteomyelitis with draining sinus, left humerus

ICD-10-CM Diagnosis Code M86.422: Chronic osteomyelitis with draining sinus, left humerus

ICD-10-CM code M86.422 identifies chronic osteomyelitis with a draining sinus in the left humerus. This diagnosis describes a serious bone infection characterized by necrotic bone and sinus tract formation. The code is a billable, specific diagnosis within the musculoskeletal system chapter, and it does not list additional coding instructions. 1 2 4

Plain-language overview

Osteomyelitis is a serious bone infection categorized as acute or chronic, with the chronic form characterized by necrotic bone and the formation of sinus tracts. 2

Chronic osteomyelitis involves symptoms occurring over a longer duration, and the infection can recur years after successful treatment if there is new trauma or compromised host immunity. 2

What this code represents

Code M86.422 represents the diagnosis of chronic osteomyelitis with draining sinus in the left humerus, and the terminology record classifies its semantic type as a disease or syndrome. 1

The official display label for M86.422 is chronic osteomyelitis with draining sinus, left humerus, distinguishing it from the right or unspecified humerus codes. 3 5

Coding details

Code M86.422 is a billable and specific code with no child codes, falling under subcategory M86.42 for chronic osteomyelitis with draining sinus of the humerus. 4

Code M86.422 is listed in Chapter 13 for diseases of the musculoskeletal system and connective tissue, specifically within the M86 to M90 range for other osteopathies. 4

Documentation considerations

The reference record for M86.422 lists no inclusion terms, no code first instructions, and no use additional code instructions for this specific diagnosis. 4

Clinical documentation for chronic osteomyelitis may involve histopathological findings rather than just illness duration, as categorization relies on identifying necrotic bone and sinus tracts. 2

What the sources add

While terminology records establish the official code hierarchy and active status for M86.422, clinical literature provides the pathological context of sinus tracts, and reference data confirms its billable status. 1 2 4

Sources

1. ICD-10-CM M86.422 terminology record — National Cancer Institute Enterprise Vocabulary Services; accessed 2026-07-27.
2. Bookshelf — ncbi.nlm.nih.gov; accessed 2026-07-27.
3. EVS Explore — evsexplore.semantics.cancer.gov; accessed 2026-07-27.
4. ICD-10-CM Code M86.422 | Vero — veroscribe.com; accessed 2026-07-27.
5. MedicareDrop — medicaredrop.com; accessed 2026-07-27.