M84.459A
Pathological fracture, hip, unspecified, initial encounter for fracture
M84.459A (also written M84459A) is a billable ICD-10-CM diagnosis code for pathological fracture, hip, unspecified, initial encounter for fracture. It is part of the FY2027 code set, effective October 1, 2026. It is one of the 928 codes in category M84 (Disorder of continuity of bone). The Alphabetic Index lists it under 1 entry. Its 7th character, A, means initial encounter for fracture. Its coding notes include 6 Excludes1 entries and 12 Excludes2 entries.
7th character
Category M84.4 requires a 7th character.
Guidelines tip
From the FY2027 Official Guidelines. ICD10Ref adds no rules of its own.
7th character A applies while the patient is in active treatment, regardless of which provider sees them. D is for routine care during healing after active treatment ends.
Excludes1
Not coded here. The listed conditions generally should not be reported together.
Excludes2
Not included here. Both codes may be reported if the patient has both conditions.
- personal history of (healed) pathological fracture (Z87.311)
- traumatic fracture of bone-see fracture, by site
Also from chapter/block level (10 notes)
- 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.
IRF 60% Rule
On the CMS list of diagnoses used to determine presumptive compliance with the IRF 60 percent rule.
Source: CMS IRF Presumptive Compliance-3, FY 2027 IRF PPS final rule files, effective for discharges on or after October 1, 2026Hospital 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 214 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 CNotes
Also from chapter/block level (1 note)
- 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 M84.459. This code adds the 7th character. 1 entry