M84.66
Pathological fracture in other disease, tibia and fibula
M84.66 is a non-billable ICD-10-CM code header for pathological fracture in other disease, tibia and fibula. Report a more specific code from it instead. It is part of the FY2027 code set, effective October 1, 2026. The more specific codes under it are M84.661 Pathological fracture in other disease, right tibia; M84.662 Pathological fracture in other disease, left tibia; M84.663 Pathological fracture in other disease, right fibula; M84.664 Pathological fracture in other disease, left fibula and 1 more. Its coding notes include a Code also instruction, 1 Excludes1 entry and 11 Excludes2 entries.
7th characters
Every code below needs one of these (defined at M84.6).
The appropriate 7th character is to be added to each code from subcategory M84.6:
- Ainitial encounter for fracture
- Dsubsequent encounter for fracture with routine healing
- Gsubsequent encounter for fracture with delayed healing
- Ksubsequent encounter for fracture with nonunion
- Psubsequent encounter for fracture with malunion
- Ssequela
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.
Code also
Two codes may be needed to describe the condition. This note gives no sequencing order.
- underlying condition
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.
- 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)
Notes
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 this code. 2 entries
More specific codes under M84.66 5
- M84.661Pathological fracture in other disease, right tibia7th char needed
- M84.662Pathological fracture in other disease, left tibia7th char needed
- M84.663Pathological fracture in other disease, right fibula7th char needed
- M84.664Pathological fracture in other disease, left fibula7th char needed
- M84.669Pathological fracture in other disease, unspecified tibia and fibula7th char needed