ICDcodes.org
FY2027

M86.9 — Osteomyelitis, unspecified

BillableUnspecifiedCC

Is M86.9 billable?

Yes, but M86.9 is an unspecified code. M86.9 is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, M86.9 is an unspecified or catch-all code. Payers apply additional scrutiny to unspecified codes and many deny them when the medical record supports a more specific option, so check the documentation before selecting M86.9 — the more specific alternatives are listed below.

M86.9 at a glance

CodeM86.9
DescriptionOsteomyelitis, unspecified
BillableYes
Code setICD-10-CM FY2027
Valid for encountersOctober 1, 2026 – September 30, 2027

Which MS-DRGs does M86.9 group to?

M86.9 sits in MDC 08 and helps define the logic of 3 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.

  • 456Spinal Fusion Except Cervical with Spinal Curvature, Malignancy, or Infection with MCCsurgical
  • 457Spinal Fusion Except Cervical with Spinal Curvature, Malignancy, or Infection with CCsurgical
  • 458Spinal Fusion Except Cervical with Spinal Curvature, Malignancy, or Infection without CC/MCCsurgical

As a secondary diagnosis, M86.9 is a complication or comorbidity (CC), which can move a stay into a higher-paying DRG.

How is M86.9 listed in the Alphabetic Index?

These are the routes through the Alphabetic Index that lead to M86.9. They show the wording a clinician may have documented, which often differs from the Tabular description.

  • Osteomyelitis (general) (infective) (localized) (neonatal) (purulent) (septic) (staphylococcal) (streptococcal) (suppurative) (with periostitis)

Inclusion terms

Alternative wording in documentation that is classified to M86.9.

  • Infection of bone NOS
  • Periostitis without osteomyelitis

Excludes1 — never code together — inherited from M86-M90

The conditions below can never be reported together with M86.9 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.

  • postprocedural osteopathies (M96.-)

Excludes1 — never code together — inherited from M86

The conditions below can never be reported together with M86.9 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.

Use additional code — inherited from M86

Report an additional code alongside M86.9 to fully describe the condition. M86.9 is sequenced first.

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

Excludes2 — not included here — inherited from Chapter 13

The conditions below are not part of M86.9, but a patient may have both at the same time. When documentation supports it, M86.9 and the excluded code may both be reported.

  • 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)

Excludes2 — not included here — inherited from M86

The conditions below are not part of M86.9, but a patient may have both at the same time. When documentation supports it, M86.9 and the excluded code may both be reported.

How long has M86.9 existed?

M86.9 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.

Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.

Which conditions are coded to M86.9?

What other codes are in the M86 family? (8)