M84.664A — Pathological fracture in other disease, left fibula, initial encounter for fracture
Is M84.664A billable?
Yes — M84.664A is billable for FY2027. M84.664A is a valid, billable ICD-10-CM code at the highest level of specificity in its branch. M84.664A may be submitted for encounters from October 1, 2026 through September 30, 2027.
M84.664A at a glance
| Code | M84.664A |
|---|---|
| Description | Pathological fracture in other disease, left fibula, initial encounter for fracture |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
| 7th character "A" | initial encounter for fracture |
What does the 7th character "A" mean in M84.664A?
In M84.664A, the 7th character A means initial encounter for fracture. The 7th character is required for M84.664A to be a valid, complete code.
Same condition, different episode of care — switch the 7th character:
Which MS-DRGs does M84.664A group to?
M84.664A 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.
- 542Pathological Fractures and Musculoskeletal and Connective Tissue Malignancy with MCCmedical
- 543Pathological Fractures and Musculoskeletal and Connective Tissue Malignancy with CCmedical
- 544Pathological Fractures and Musculoskeletal and Connective Tissue Malignancy without CC/MCCmedical
As a secondary diagnosis, M84.664A is a complication or comorbidity (CC), which can move a stay into a higher-paying DRG.
How is M84.664A listed in the Alphabetic Index?
The Alphabetic Index lists these routes under M84.66, the nearest indexed parent of M84.664A. Use them to find the family, then select the specific code.
- Fracture, pathological › due to › specified disease NEC › fibula (pathologic)
- Fracture, pathological › due to › specified disease NEC › tibia (pathologic)
Excludes1 — never code together — inherited from M84.6
The conditions below can never be reported together with M84.664A on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
- pathological fracture in osteoporosis (M80.-)
Excludes2 — not included here — inherited from Chapter 13
The conditions below are not part of M84.664A, but a patient may have both at the same time. When documentation supports it, M84.664A 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 M84
The conditions below are not part of M84.664A, but a patient may have both at the same time. When documentation supports it, M84.664A and the excluded code may both be reported.
- traumatic fracture of bone-see fracture, by site
Code also — inherited from M84.6
Two codes may be needed to describe the condition fully. Whether M84.664A is sequenced first depends on the reason for the encounter.
- underlying condition
How long has M84.664A existed?
M84.664A 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.