New for FY2027 ICD-10-CM · October 1, 2026
M86.8X59: Other osteomyelitis, unspecified thigh
By the HCC Buddy Coding Team
The official ICD-10-CM descriptor is Other osteomyelitis, unspecified thigh. The FY2027 annual edition starts October 1, 2026. Check the edition that applies to the encounter or inpatient discharge, including any April update.
Billable code. Verified against the official FY2027 order file.
FY2027 Tabular instructions
Instructions below include applicable chapter, section and parent-code notes. Each note identifies where it appears in the official source.
Instructional note
Use an external cause code following the code for the musculoskeletal condition, if applicable, to identify the cause of the musculoskeletal condition
Source: M00-M99 (chapter, inherited).
Excludes2
arthropathic psoriasis (L40.5-)
Source: M00-M99 (chapter, inherited).
Excludes2
certain conditions originating in the perinatal period (P04-P96)
Source: M00-M99 (chapter, inherited).
Excludes2
certain infectious and parasitic diseases (A00-B99)
Source: M00-M99 (chapter, inherited).
Excludes2
compartment syndrome (traumatic) (T79.A-)
Source: M00-M99 (chapter, inherited).
Excludes2
complications of pregnancy, childbirth and the puerperium (O00-O9A)
Source: M00-M99 (chapter, inherited).
Excludes2
congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
Source: M00-M99 (chapter, inherited).
Excludes2
endocrine, nutritional and metabolic diseases (E00-E88)
Source: M00-M99 (chapter, inherited).
Excludes2
injury, poisoning and certain other consequences of external causes (S00-T88)
Source: M00-M99 (chapter, inherited).
Excludes2
neoplasms (C00-D49)
Source: M00-M99 (chapter, inherited).
Excludes2
symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
Source: M00-M99 (chapter, inherited).
Excludes1
postprocedural osteopathies (M96.-)
Source: M86-M90 (section, inherited).
Instructional note
code (B95-B97) to identify infectious agent
Source: M86 (category, inherited).
Instructional note
code to identify major osseous defect, if applicable (M89.7-)
Source: M86 (category, inherited).
Excludes1
osteomyelitis due to:
Source: M86 (category, inherited).
Excludes1
echinococcus (B67.2)
Source: M86 (category, inherited).
Excludes1
gonococcus (A54.43)
Source: M86 (category, inherited).
Excludes1
salmonella (A02.24)
Source: M86 (category, inherited).
Excludes2
ostemyelitis of:
Source: M86 (category, inherited).
Excludes2
orbit (H05.0-)
Source: M86 (category, inherited).
Excludes2
petrous bone (H70.2-)
Source: M86 (category, inherited).
Excludes2
vertebra (M46.2-)
Source: M86 (category, inherited).
Instructional note
Brodie's abscess
Source: M86.8 (self, inherited).
Compare the FY2027 additions, removals and billable-status changes
What does M86.8X59 mean in FY2027?
The official ICD-10-CM descriptor is Other osteomyelitis, unspecified thigh. The FY2027 annual edition starts October 1, 2026. Check the edition that applies to the encounter or inpatient discharge, including any April update.
When did M86.8X59 become an ICD-10-CM code?
M86.8X59 is new for FY2027 ICD-10-CM, effective October 1, 2026. It is absent from the FY2026 April order file. Use the code set that applies to the encounter or inpatient discharge date, and check the official Tabular instructions.
Is M86.8X59 billable in FY2027?
The FY2027 order file marks M86.8X59 as billable. Check the complete Tabular instructions and documentation before assigning it.
Does M86.8X59 map to an HCC?
M86.8X59 is not in the current CMS mapping file (it is new for FY2027), and CMS has not yet published payment year 2028 mappings. No HCC category or RAF coefficient is shown.
Source: CMS FY2027 ICD-10-CM order file. Payment model: CMS CY 2027 Rate Announcement. Read the FY2027 Official Guidelines.