C40.21 — Malignant neoplasm of long bones of right lower limb
Is C40.21 billable?
Yes — C40.21 is billable for FY2027. C40.21 is a valid, billable ICD-10-CM code at the highest level of specificity in its branch. C40.21 may be submitted for encounters from October 1, 2026 through September 30, 2027.
C40.21 at a glance
| Code | C40.21 |
|---|---|
| Description | Malignant neoplasm of long bones of right lower limb |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
Which MS-DRGs does C40.21 group to?
C40.21 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, C40.21 is a complication or comorbidity (CC), which can move a stay into a higher-paying DRG.
How is C40.21 listed in the Alphabetic Index?
The Alphabetic Index lists these routes under C40.2, the nearest indexed parent of C40.21. Use them to find the family, then select the specific code.
- Adamantinoma › tibial
- Ameloblastoma › tibial
- Adamantinoma › long bones › lower limb
- Ameloblastoma › long bones › lower limb
Excludes1 — never code together — inherited from C40-C41
The conditions below can never be reported together with C40.21 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 C40
Report an additional code alongside C40.21 to fully describe the condition. C40.21 is sequenced first.
- code to identify major osseous defect, if applicable (M89.7-)
How long has C40.21 existed?
C40.21 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.