2027 ICD-10-CM Diagnosis Code L98.425Non-pressure chronic ulcer of back with muscle involvement without evidence of necrosis

ICD-10-CM Codes›L00–L99›L80-L99›L98

ICD-10-CM L98.425
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

L98.425 is a billable ICD-10-CM diagnosis code for non-pressure chronic ulcer of back with muscle involvement without evidence of necrosis. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 573 through 575, 592 through 594. 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 325 closely related codes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Non-pressure ulcer of skin.

For Medicare Advantage risk adjustment, L98.425 maps to CMS-HCC Category 380 (Chronic Ulcer of Skin, Except Pressure, Through to Bone or Muscle) under the V28 model, adding a risk factor of about 1.078 for a community, non-dual, aged beneficiary in payment year 2027.

Code Identity

ICD-10-CM Code
L98.425
Billable Status
Yes — Valid for Submission
Code Describes
Non-pressure chronic ulcer of back with muscle involvement without evidence of necrosis
Short Description
Non-prs chr ulcer of back with muscle invl w/o evd of necr
Parent Code
L98.42
Non-pressure chronic ulcer of back

Code Classification

ChapterL00–L99Diseases of the skin and subcutaneous tissue
SectionL80-L99Other disorders of the skin and subcutaneous tissue
CategoryL98Other disorders of skin and subcutaneous tissue, not elsewhere classified
This CodeL98.425Non-pressure chronic ulcer of back with muscle involvement without evidence of necrosis

Medicare Risk Adjustment (HCC)Billing

L98.425 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.

CMS-HCC V28 Category (Payment Model)
HCC 380— Chronic Ulcer of Skin, Except Pressure, Through to Bone or Muscle
Payment HCC · PY 2027 one of 152 ICD-10-CM codes in this category
Risk Adjustment Factor (RAF) Weight
+1.078
community, non-dual, aged · ranges 0.839–1.422 across segments
Hierarchy
Superseded by HCC 379
a more severe related category takes the payment when both are reported
Prior Model (CMS-HCC V24)
HCC 161
V24 retired V28 pays 100% of MA risk scores since PY 2026
Other CMS Models
PACE (CMS-HCC V22): HCC 161 · ESRD (V21): HCC 161 · ESRD (V24): HCC 161
ESRD V21 weights: 0.119 dialysis, 0.225–0.503 functioning graft · ESRD V24 weights: 0.127 dialysis, 0.243–0.782 functioning graft
Part D (RxHCC)
RxHCC 311 — Chronic Ulcer of Skin, Except Pressure
also risk-adjusts in the Part D prescription drug model (V08)

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 L98.425: its own notes plus those printed at L98.4 and Chapter 12. A note printed at a category, block or chapter applies to every code under it.

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.

From L98.4 Non-pressure chronic ulcer of skin, not elsewhere classified applies to 64 codes
From Chapter 12 (L00-L99) Diseases of the skin and subcutaneous tissue applies to 1,001 codes
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • lipomelanotic reticulosis (I89.8)
  • neoplasms (C00-D49)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
  • systemic connective tissue disorders (M30-M36)
  • viral warts (B07.-)

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name L98.425, its category, or a range that includes it.

Use Additional Code 6

These codes say to use an additional code from the note, and L98.425 is one of the codes named.

  • T65.84 Toxic effect of xylazine
    non-pressure chronic ulcer of skin, not elsewhere classified (L98.4-) names L98.4-, which includes this code
  • E08.622 Diabetes mellitus due to underlying condition with other skin ulcer
    code to identify site of ulcer (L97.1-L97.9, L98.41-L98.49) names L98.41-L98.49, which includes this code
  • E09.622 Drug or chemical induced diabetes mellitus with other skin ulcer
    code to identify site of ulcer (L97.1-L97.9, L98.41-L98.49) names L98.41-L98.49, which includes this code
  • E10.622 Type 1 diabetes mellitus with other skin ulcer
    code to identify site of ulcer (L97.1-L97.9, L98.41-L98.49) names L98.41-L98.49, which includes this code
  • E11.622 Type 2 diabetes mellitus with other skin ulcer
    code to identify site of ulcer (L97.1-L97.9, L98.41-L98.49) names L98.41-L98.49, which includes this code
  • E13.622 Other specified diabetes mellitus with other skin ulcer
    code to identify site of ulcer (L97.1-L97.9, L98.41-L98.49) names L98.41-L98.49, which includes this code

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

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

CCSR SKN004
Non-pressure ulcer of skin
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Muscle Disorders

Your muscles help you move and help your body work. Different types of muscles have different jobs. There are many problems that can affect muscles. Muscle disorders can cause weakness, pain or even paralysis.

Read the full article at MedlinePlus

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

Convert L98.425 to ICD-9-CMHistory

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

ICD-9-CM
707.8 Chronic skin ulcer NEC
Approximate The match is approximate rather than exact.

Code History & ChangesHistory

Replacement L98.425 replaces the following previously assigned code(s):

  • L98.429 - Non-pressure chronic ulcer of back with unspecified severity
FY 2019AddedAdded to the ICD-10-CM code setEffective October 1, 2018.
FY 2020–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About L98.425Overview

Is L98.425 (Non-pressure chronic ulcer of back) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report non-pressure chronic ulcer of back with muscle involvement without evidence of necrosis on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does L98.425 group to?

When non-pressure chronic ulcer of back with muscle involvement without evidence of necrosis is the principal diagnosis on an inpatient stay, it groups to MS-DRG 592, 573, 574, 575, 593, 594, with relative weights from 0.7347 to 6.3547 depending on complications. Higher weights mean higher Medicare reimbursement.

Is L98.425 a CC or MCC?

CMS lists L98.425 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 325 closely related codes in its exclusion list.

What is the ICD-9 equivalent of L98.425?

Under the General Equivalence Mappings, non-pressure chronic ulcer of back with muscle involvement without evidence of necrosis converts to ICD-9-CM 707.8 (chronic skin ulcer NEC). The mapping is approximate, so confirm the match fits the documentation.

What HCC is L98.425?

L98.425 (non-pressure chronic ulcer of back with muscle involvement without evidence of necrosis) maps to CMS-HCC Category 380 (Chronic Ulcer of Skin, Except Pressure, Through to Bone or Muscle), commonly written as HCC 380, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It mapped to HCC 161 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 311.

Does L98.425 risk-adjust for Medicare Advantage payment?

Yes. When documented and reported on a Medicare Advantage encounter, L98.425 adds a risk adjustment factor of about 1.078 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.839 to 1.422 depending on the payment segment). A more severe related category (HCC 379) supersedes it when both are reported. See the full factor table on the HCC 380 category page.