M86.00

Acute hematogenous osteomyelitis, unspecified site

FY2027Chapter 13: Diseases of the musculoskeletal system and connective tissue/M86–M90 Other osteopathies

BillableComplete code, valid to report
Care settingsHospital CC

M86.00 (also written M8600) is a billable ICD-10-CM diagnosis code for acute hematogenous osteomyelitis, unspecified site. It is part of the FY2027 code set, effective October 1, 2026. It is one of the 195 codes in category M86 (Osteomyelitis). The Alphabetic Index lists it under 1 entry. Its coding notes include a Use additional code instruction, 5 Excludes1 entries and 14 Excludes2 entries.

Use additional code

Add the listed code as a secondary code, if known.

Inherited from M86 Osteomyelitis
  • code (B95-B97) to identify infectious agent
  • code to identify major osseous defect, if applicable (M89.7-)

Excludes1

Not coded here. The listed conditions generally should not be reported together.

Inherited from M86 Osteomyelitis
Also from chapter/block level (1 note)
Inherited from M86–M90 Other osteopathies
  • postprocedural osteopathies (M96.-)

Excludes2

Not included here. Both codes may be reported if the patient has both conditions.

Inherited from M86 Osteomyelitis
Also from chapter/block level (10 notes)
Inherited from Chapter 13 Diseases of the musculoskeletal system and connective tissue
  • arthropathic psoriasis (L40.5-)
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • compartment syndrome (traumatic) (T79.A-)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • injury, poisoning and certain other consequences of external causes (S00-T88)
  • neoplasms (C00-D49)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)

Care settings

How CMS programs treat this code. These are CMS claim edits and list entries, not coverage or eligibility rules.

Hospital CC

Counts as a complication or comorbidity (CC) when reported as a secondary diagnosis on an inpatient claim. It does not count when the principal diagnosis is one of the 220 codes in its exclusion list. Some MS-DRGs also ignore a CC or MCC that defines the DRG.

Source: CMS MS-DRG Definitions Manual v44, effective October 1, 2026, Appendix C

Notes

Also from chapter/block level (1 note)
Inherited from Chapter 13 Diseases of the musculoskeletal system and connective tissue
  • Use an external cause code following the code for the musculoskeletal condition, if applicable, to identify the cause of the musculoskeletal condition

Alphabetic Index terms

Terms the official Alphabetic Index lists for this code. 1 entry