2026 ICD-10-CM Diagnosis Code C41.4Malignant neoplasm of pelvic bones, sacrum and coccyx

ICD-10-CM Codes›C00–D49›C40-C41›C41

ICD-10-CM C41.4
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

C41.4 is a billable ICD-10-CM diagnosis code for malignant neoplasm of pelvic bones, sacrum and coccyx. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 542 through 544. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 9 closely related codes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Bone cancer.

For Medicare Advantage risk adjustment, C41.4 maps to CMS-HCC Category 21 (Lymphoma and Other Cancers) under the V28 model, adding a risk factor of about 0.671 for a community, non-dual, aged beneficiary in payment year 2026.

Code Identity

ICD-10-CM Code
C41.4
Billable Status
Yes — Valid for Submission
Code Describes
Malignant neoplasm of pelvic bones, sacrum and coccyx
Short Description
Malignant neoplasm of pelvic bones, sacrum and coccyx
Same as the full description in the CMS dataset.
Parent Code
C41
Malignant neoplasm of bone and articular cartilage of other and unspecified sites

Code Classification

ChapterC00–D49Neoplasms
SectionC40-C41Malignant neoplasms of bone and articular cartilage
CategoryC41Malignant neoplasm of bone and articular cartilage of other and unspecified sites
This CodeC41.4Malignant neoplasm of pelvic bones, sacrum and coccyx

Medicare Risk Adjustment (HCC)Billing

C41.4 maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2026.

CMS-HCC V28 Category (Payment Model)
HCC 21— Lymphoma and Other Cancers
Payment HCC · PY 2026 one of 463 ICD-10-CM codes in this category
Risk Adjustment Factor (RAF) Weight
+0.671
community, non-dual, aged · ranges 0.493–0.739 across segments
Hierarchy
Superseded by HCC 17, HCC 18, HCC 19, and HCC 20
a more severe related category takes the payment when both are reported
Prior Model (CMS-HCC V24)
HCC 10
V24 retired V28 pays 100% of MA risk scores since PY 2026
Other CMS Models
PACE (CMS-HCC V22): HCC 10 · ESRD (V21): HCC 10 · ESRD (V24): HCC 10
ESRD V21 weights: 0.136 dialysis, 0.451–0.668 functioning graft · ESRD V24 weights: 0.111 dialysis, 0.467–0.780 functioning graft
Part D (RxHCC)
RxHCC 22 — Prostate, Breast, Bladder, and Other Cancers and Tumors
also risk-adjusts in the Part D prescription drug model (V08)

Source: CMS Payment Year 2026 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Carcinoma of pelvic bones, sacrum and coccyx
  • Chondrosarcoma of bone of pelvic wall
  • Chordoma of coccyx
  • Chordoma of pelvis
  • Chordoma of sacrum
  • Chordoma of vertebral column
  • Ewing sarcoma of bone of pelvis
  • Malignant neoplasm of coccygeal vertebra
  • Malignant neoplasm of pelvic bones, sacrum and coccyx
  • Malignant neoplasm of sacral vertebra
  • Malignant neoplasm of vertebra
  • Malignant sacral teratoma
  • Malignant teratoma
  • Neoplasm of bone of sacrum
  • Neoplasm of coccyx
  • Neoplasm of ilium
  • Neoplasm of ischium
  • Neoplasm of pubis
  • Primary carcinoma of pelvic bones, sacrum and coccyx
  • Primary chondrosarcoma of articular cartilage
  • Primary chondrosarcoma of articular cartilage of limb
  • Primary chondrosarcoma of articular cartilage of pelvis
  • Primary chondrosarcoma of bone of pelvis
  • Primary Ewing sarcoma of articular cartilage of limb
  • Primary Ewing sarcoma of articular cartilage of pelvis
  • Primary Ewing sarcoma of bone of pelvis
  • Primary malignant neoplasm of coccyx
  • Primary malignant neoplasm of ilium
  • Primary malignant neoplasm of ischium
  • Primary malignant neoplasm of pelvic bones, sacrum and coccyx
  • Primary malignant neoplasm of pubis
  • Primary malignant neoplasm of sacrococcygeal region
  • Primary malignant neoplasm of sacrum
  • Primary osteosarcoma of articular cartilage of limb
  • Primary osteosarcoma of articular cartilage of lower limb
  • Primary osteosarcoma of articular cartilage of pelvis
  • Primary osteosarcoma of pelvis
  • Sacrococcygeal teratoma
  • Sarcoma of bone of pelvis
  • Sarcoma of coccyx
  • Sarcoma of sacrum

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR NEO023
Bone cancer
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Coccyx

    the last bone in the vertebral column in tailless primates considered to be a vestigial tail-bone consisting of three to five fused vertebrae.

  • Ischium

    one of three bones that make up the coxal bone of the pelvic girdle. in tetrapods, it is the part of the pelvis that projects backward on the ventral side, and in primates, it bears the weight of the sitting animal.

  • Pubic Bone

    a bone that forms the lower and anterior part of each side of the hip bone.

Table of NeoplasmsClinical

Anatomical sites in the Table of Neoplasms that reference this code family.

SiteMalig.
Primary		Malig.
Secondary		Ca
in situ		BenignUncertainUnspec.
bone (periosteum) › acetabulumC41.4C79.51–D16.8D48.0D49.2
bone (periosteum) › coccygeal vertebraC41.4C79.51–D16.8D48.0D49.2
bone (periosteum) › coccyxC41.4C79.51–D16.8D48.0D49.2
bone (periosteum) › hipC41.4C79.51–D16.8D48.0D49.2
bone (periosteum) › iliumC41.4C79.51–D16.8D48.0D49.2
bone (periosteum) › innominateC41.4C79.51–D16.8D48.0D49.2
bone (periosteum) › ischiumC41.4C79.51–D16.8D48.0D49.2
bone (periosteum) › pelvicC41.4C79.51–D16.8D48.0D49.2
bone (periosteum) › pubicC41.4C79.51–D16.8D48.0D49.2
bone (periosteum) › sacral vertebraC41.4C79.51–D16.8D48.0D49.2
bone (periosteum) › sacrumC41.4C79.51–D16.8D48.0D49.2
bone (periosteum) › spine, spinal (column) › coccyxC41.4C79.51–D16.8D48.0D49.2
bone (periosteum) › spine, spinal (column) › sacrumC41.4C79.51–D16.8D48.0D49.2
bone (periosteum) › vertebra (column) › coccyxC41.4C79.51–D16.8D48.0D49.2
bone (periosteum) › vertebra (column) › sacrumC41.4C79.51–D16.8D48.0D49.2
coccygeal › vertebraC41.4C79.51–D16.8D48.0D49.2
coccyxC41.4C79.51–D16.8D48.0D49.2
iliumC41.4C79.51–D16.8D48.0D49.2
ischiumC41.4C79.51–D16.8D48.0D49.2
pelvis, pelvic › boneC41.4C79.51–D16.8D48.0D49.2
pubic boneC41.4C79.51–D16.8D48.0D49.2
sacrum, sacral (vertebra)C41.4C79.51–D16.8D48.0D49.2
spine, spinal (column) › coccyxC41.4C79.51–D16.8D48.0D49.2
spine, spinal (column) › sacrumC41.4C79.51–D16.8D48.0D49.2
symphysis pubisC41.4C79.51–D16.8D48.0D49.2
vertebra (column) › coccyxC41.4C79.51–D16.8D48.0D49.2
vertebra (column) › sacrumC41.4C79.51–D16.8D48.0D49.2

Patient EducationClinical

Bone Cancer

Cancer that starts in a bone is uncommon. Cancer that has spread to the bone from another part of the body is more common.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert C41.4 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
170.6 Mal neo pelvic girdle
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About C41.4Overview

What is the ICD-10 code for malignant neoplasm of pelvic bones, sacrum and coccyx?

The ICD-10-CM code for malignant neoplasm of pelvic bones, sacrum and coccyx is C41.4 (sometimes written as C414). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Is C41.4 a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report malignant neoplasm of pelvic bones, sacrum and coccyx on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does C41.4 group to?

When malignant neoplasm of pelvic bones, sacrum and coccyx is the principal diagnosis on an inpatient stay, it groups to MS-DRG 542, 543, 544, with relative weights from 0.7546 to 1.7665 depending on complications. Higher weights mean higher Medicare reimbursement.

Is C41.4 a CC or MCC?

CMS lists C41.4 as a CC (complication or comorbidity) for FY 2026. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 9 closely related codes in its exclusion list.

What is the ICD-9 equivalent of C41.4?

Under the General Equivalence Mappings, malignant neoplasm of pelvic bones, sacrum and coccyx converts to ICD-9-CM 170.6 (mal neo pelvic girdle). The mapping is a direct match.

What HCC is C41.4?

C41.4 (malignant neoplasm of pelvic bones, sacrum and coccyx) maps to CMS-HCC Category 21 (Lymphoma and Other Cancers), commonly written as HCC 21, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2026. It mapped to HCC 10 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. In the Part D prescription drug model it maps to RxHCC 22.

Does C41.4 risk-adjust for Medicare Advantage payment?

Yes. When documented and reported on a Medicare Advantage encounter, C41.4 adds a risk adjustment factor of about 0.671 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.493 to 0.739 depending on the payment segment). A more severe related category (HCC 17, HCC 18, HCC 19, and HCC 20) supersedes it when both are reported. See the full factor table on the HCC 21 category page.