C48.1
Malignant neoplasm of specified parts of peritoneum
HCC risk adjustment mapping
CMS-HCC V28
Lung and Other Severe Cancers
CMS-HCC ESRD V24
Lung and Other Severe Cancers
RxHCC V08
Prostate, Breast, Bladder, and Other Cancers and Tumors
Coding notes
Excludes 1 never coded together · Excludes 2 may co-exist
Malignant neoplasm of cul-de-sac Malignant neoplasm of mesentery Malignant neoplasm of mesocolon Malignant neoplasm of omentum Malignant neoplasm of parietal peritoneum Malignant neoplasm of pelvic peritoneum
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). (C00-C96) Malignant neoplasms (C00-C96) (C00-C75) Malignant neoplasms, stated or presumed to be primary (of specified sites), and certain specified histologies, except neuroendocrine, and of lymphoid, hematopoietic and related tissue (C00-C75)
Official Guidelines for C48.1
FY 2026 ›Subsections
- I.C.2.aAdmission/Encounter for treatment of primary site
- I.C.2.bAdmission/Encounter for treatment of secondary site
- I.C.2.cCoding and sequencing of complications
- I.C.2.dPrimary malignancy previously excised
- I.C.2.eAdmissions/Encounters involving antineoplastic chemotherapy, immunotherapy and radiation therapy
- I.C.2.fAdmission/encounter to determine extent of malignancy
- I.C.2.gSymptoms, signs, and abnormal findings listed in Chapter 18 associated with neoplasms
- I.C.2.hAdmission/encounter for pain control/management
- I.C.2.iMalignancy in two or more noncontiguous sites
- I.C.2.jDisseminated malignant neoplasm, unspecified
- I.C.2.kMalignant neoplasm without specification of site
- I.C.2.lSequencing of neoplasm codes
- I.C.2.mCurrent malignancy versus personal history of malignancy
- I.C.2.nLeukemia, Multiple Myeloma, and Malignant Plasma Cell
- I.C.2.oAftercare following surgery for neoplasm
- I.C.2.pFollow-up care for completed treatment of a malignancy
- I.C.2.qProphylactic organ removal for prevention of malignancy
- I.C.2.rMalignant neoplasm associated with transplanted organ
- I.C.2.sBreast Implant Associated Anaplastic Large Cell Lymphoma
- I.C.2.tSecondary malignant neoplasm of lymphoid tissue
In the Table of Neoplasms
One of them: Neoplasm, neoplastic > cul-de-sac(Douglas'), column Malignant Primary.
cul-de-sac(Douglas') in every column
This row belongs to cul-de-sac(Douglas'). Other sites sharing C48.1 may differ in the remaining columns — check the one in your documentation.
- Malignant PrimaryC48.11.136HCC20maps to HCC20
- Malignant SecondaryC78.64.209HCC17maps to HCC17
- BenignD20.10.000maps to no HCC category
- Uncertain BehaviorD48.40.000maps to no HCC category
- Unspecified BehaviorD49.00.000maps to no HCC category
The column is chosen by the documentation, not by the coder. Behaviour follows the pathology report (Guideline I.C.2). Coefficients are Community, Non-Dual, Aged under CMS-HCC V28 PY2027. How these figures were derived.