C41.9 Malignant neoplasm of bone and articular cartilage, unspecified

Billable ICD-10-CM code, FY2026. Acts as a Complication or Comorbidity (CC) as a secondary diagnosis.

Applies from C41 Malignant neoplasm of bone and articular cartilage of other and unspecified sites

Excludes1 (never code together)

• malignant neoplasm of bones of limbs (C40.-)
• malignant neoplasm of cartilage of ear (C49.0)
• malignant neoplasm of cartilage of eyelid (C49.0)
• malignant neoplasm of cartilage of larynx (C32.3)
• malignant neoplasm of cartilage of limbs (C40.-)
• malignant neoplasm of cartilage of nose (C30.0)

Risk adjustment (HCC)

• CMS-HCC V28: HCC 21 — Lymphoma and Other Cancers
• CMS-HCC V22: HCC 10 — Lymphoma and Other Cancers
• RxHCC V08: HCC 22 — Prostate, Breast, Bladder, and Other Cancers and Tumors
• ESRD V24: HCC 10

MS-DRG index

Defines the logic of DRG(s) 542-544 in MDC 08.

Approximate ICD-9-CM (GEMs)

• 170.9 Malignant neoplasm of bone and articular cartilage, site unspecified (approximate)

Code annotations containing back-references to C41.9

Back-references to C41

• Type 1 Excludes: C49 Malignant neoplasm of other connective and soft tissue ("articular (C40-C41)")
• Code First: M90.6 Osteitis deformans in neoplastic diseases ("the neoplasm (C40.-, C41.-)")

Diagnosis Index entries for C41.9

• Osteitis › deformans › in (due to) › malignant neoplasm of bone (see also, Neoplasm, malignant, by site)

Nearby codes

• C41.0 Malignant neoplasm of bones of skull and face
• C41.1 Malignant neoplasm of mandible
• C41.2 Malignant neoplasm of vertebral column
• C41.3 Malignant neoplasm of ribs, sternum and clavicle
• C41.4 Malignant neoplasm of pelvic bones, sacrum and coccyx
• C41.9 Malignant neoplasm of bone and articular cartilage, unspecified (this code)