2027 ICD-10-CM Diagnosis Code C58Malignant neoplasm of placenta
ICD-10-CM Codes›C00–D49›C51-C58›C58
- Billable — Valid for Submission
- Risk Adjusts — HCC 22
- Chronic Condition
C58 is a billable ICD-10-CM diagnosis code for malignant neoplasm of placenta. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 731 through 733, 754 through 756. The code is restricted by the Medicare Code Editor to maternity cases (age 9 through 64). Coders also document this condition as choriocarcinoma. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Female reproductive system cancers - all other types.
For Medicare Advantage risk adjustment, C58 maps to CMS-HCC Category 22 (Bladder, Colorectal, and Other Cancers) under the V28 model, adding a risk factor of about 0.363 for a community, non-dual, aged beneficiary in payment year 2027.
Code Identity
Code Classification
Code EditsBilling
Medicare Code Editor checks that affect claim validity for C58.
Medicare Risk Adjustment (HCC)Billing
C58 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 2027.
Source: CMS Payment Year 2027 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.
- Choriocarcinoma
- Choriocarcinoma of placenta
- Epithelioid trophoblastic tumor
- Gestational choriocarcinoma
- Gestational trophoblastic disease
- Gestational trophoblastic neoplasia
- Malignant neoplastic disease in pregnancy
- Neoplasm of placenta
- Primary malignant neoplasm of placenta
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to C58: its own notes plus those printed at block C51-C58 and Chapter 2. A note printed at a category, block or chapter applies to every code under it.
Includes
Further defines, or gives examples of, the content of the category.
- choriocarcinoma NOS
- chorionepithelioma NOS
- malignant neoplasm of skin of female genital organs
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
Notes
General instructions on how these codes are used.
- Functional activity
- All neoplasms are classified in this chapter, whether they are functionally active or not. An additional code from Chapter 4 may be used, to identify functional activity associated with any neoplasm.
- Morphology [Histology]
- Chapter 2 classifies neoplasms primarily by site (topography), with broad groupings for behavior, malignant, in situ, benign, etc. The Table of Neoplasms should be used to identify the correct topography code. In a few cases, such as for malignant melanoma and certain neuroendocrine tumors, the morphology (histologic type) is included in the category and codes.
- Primary malignant neoplasms overlapping site boundaries
- A primary malignant neoplasm that overlaps two or more contiguous (next to each other) sites should be classified to the subcategory/code .8 ('overlapping lesion'), unless the combination is specifically indexed elsewhere. For multiple neoplasms of the same site that are not contiguous, such as tumors in different quadrants of the same breast, codes for each site should be assigned.
- Malignant neoplasm of ectopic tissue
- Malignant neoplasms of ectopic tissue are to be coded to the site mentioned, e.g., ectopic pancreatic malignant neoplasms are coded to pancreas, unspecified (C25.9).
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name C58, its category, or a range that includes it.
Applicable To 2
These notes mention C58.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Carcinoma (malignant) See Also: Neoplasm, by site, malignant;
Choriocarcinoma See: Neoplasm, malignant, by site;
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Malignant Placental Neoplasm
a primary or metastatic neoplasm that affects the placenta.
Table of NeoplasmsClinical
Patient EducationClinical
Tumors and Pregnancy
Tumors during pregnancy are rare, but they can happen. Tumors can be either benign (not cancer) or malignant (cancer). The most common cancers in pregnancy include breast cancer, thyroid cancer, cervical cancer, lymphoma, and melanoma. Cancer itself rarely harms the fetus, and some cancer treatments are safe during pregnancy.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert C58 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About C58Overview
What is the ICD-10 code for malignant neoplasm of placenta?
The ICD-10-CM code for malignant neoplasm of placenta is C58. It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is C58 (Malignant neoplasm of placenta) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report malignant neoplasm of placenta on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does C58 group to?
When malignant neoplasm of placenta is the principal diagnosis on an inpatient stay, it groups to MS-DRG 732, 755, 756, 754, 733, 731, with relative weights from 0.8583 to 3.5462 depending on complications. Higher weights mean higher Medicare reimbursement.
Who can C58 be reported for?
The Medicare Code Editor checks malignant neoplasm of placenta against patient demographics: this code is intended for maternity cases (age 9 through 64). Claims outside these limits are flagged as inconsistent.
Can C58 be reported with D39.2?
Not as a rule. The Excludes1 note on C58 lists "chorioadenoma (destruens) (D39.2)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
What HCC is C58?
C58 (malignant neoplasm of placenta) maps to CMS-HCC Category 22 (Bladder, Colorectal, and Other Cancers), commonly written as HCC 22, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. 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 C58 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, C58 adds a risk adjustment factor of about 0.363 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.314 to 0.410 depending on the payment segment). A more severe related category (HCC 17, HCC 18, HCC 19, HCC 20, and HCC 21) supersedes it when both are reported. See the full factor table on the HCC 22 category page.
