2027 ICD-10-CM Diagnosis Code C88.31Immunoproliferative small intestinal disease, in remission
ICD-10-CM Codes›C00–D49›C81-C96›C88
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- Risk Adjusts — HCC 21
- Chronic Condition
C88.31 is a billable ICD-10-CM diagnosis code for immunoproliferative small intestinal disease, in remission. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 820 through 825, 840 through 842. 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 113 closely related codes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Leukemia in remission.
For Medicare Advantage risk adjustment, C88.31 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 2027.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
C88.31 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.
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to C88.31: its own notes plus those printed at C88, block C81-C96, and Chapter 2. A note printed at a category, block or chapter applies to every code under it.
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
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 C88.31, its category, or a range that includes it.
Applicable To 1
These notes mention C88.31.
- Z85.79 Personal history of other malignant neoplasms of lymphoid, hematopoietic and related tissues
Excludes1 1
These codes carry an Excludes1 note naming C88.31: they are not reported together with it, unless the two conditions are unrelated.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Immunoproliferative Small Intestinal Disease
a condition that is caused by hyperplasia of lymphocytes in the small intestine (intestine, small) and the mesenteric lymph nodes. these lymphocytes produce an anomalous alpha heavy chain protein. generally, these ipsid patients have either concurrent lymphoma or develop lymphoma within a few years. the disease was first described in the mediterranean region and is characterized by malabsorption; weight loss; diarrhea; and steatorrhea.
Patient EducationClinical
Lymphoma
Lymphoma is a cancer of a part of the immune system called the lymph system. There are many types of lymphoma. One type is Hodgkin disease. The rest are called non-Hodgkin lymphomas.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Code History & ChangesHistory
Replacement C88.31 replaces the following previously assigned code(s):
- Z85.79 - Prsnl hx of malig neoplm of lymphoid, hematpoetc & rel tiss
Questions About C88.31Overview
What is the ICD-10 code for immunoproliferative small intestinal disease, in remission?
The ICD-10-CM code for immunoproliferative small intestinal disease, in remission is C88.31 (sometimes written as C8831). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is C88.31 (Immunoproliferative small intestinal disease) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report immunoproliferative small intestinal disease, in remission on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does C88.31 group to?
When immunoproliferative small intestinal disease, in remission is the principal diagnosis on an inpatient stay, it groups to MS-DRG 841, 821, 822, 825, 842, 824, 840, 820, 823, with relative weights from 0.9948 to 6.2454 depending on complications. Higher weights mean higher Medicare reimbursement.
Is C88.31 a CC or MCC?
CMS lists C88.31 as a CC (complication or comorbidity) for FY 2027. 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 113 closely related codes in its exclusion list.
Can C88.31 be reported with a code from C85.1?
Not as a rule. The Excludes1 note at C88, which applies to C88.31, lists "B-cell lymphoma, unspecified (C85.1-)". 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 C88.31?
C88.31 (immunoproliferative small intestinal disease, in remission) 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 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 21.
Does C88.31 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, C88.31 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.
