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ICD-10-CM 2027 diagnosis code

L04.1Acute lymphadenitis of trunk

✓ Billable / specific

L04.1 is a valid, billable ICD-10-CM code for acute lymphadenitis of trunk. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About L04.1

L04.1 is the ICD-10-CM diagnosis code for acute lymphadenitis of trunk. It belongs to category L04 (acute lymphadenitis), block L00-L08 (infections of the skin and subcutaneous tissue) and chapter 12 (diseases of the skin and subcutaneous tissue). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within L04 (acute lymphadenitis), L04.1 is specifically for acute lymphadenitis of trunk. Related codes cover of face, head and neck (L04.0), of upper limb (L04.2), of lower limb (L04.3), of other sites (L04.8) and unspecified (L04.9).

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 791 (Prematurity with Major Problems, relative weight 4.1075), DRG 793 (Full Term Neonate with Major Problems, relative weight 4.2195), DRG 814 (Reticuloendothelial and Immunity Disorders with MCC, relative weight 2.0729), DRG 815 (Reticuloendothelial and Immunity Disorders with CC, relative weight 1.0444) and DRG 816 (Reticuloendothelial and Immunity Disorders without CC/MCC, relative weight 0.7381), in MDC 15 (Newborns and Other Neonates with Conditions Originating in the Perinatal Period) and MDC 16 (Diseases and Disorders of the Blood and Blood Forming Organs and Immunological Disorders), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 683 (acute lymphadenitis).

Notes that apply from higher levels

Instructions written at a parent level also apply to L04.1.

› From L04 Acute lymphadenitis
Includes
  • abscess (acute) of lymph nodes, except mesenteric
  • acute lymphadenitis, except mesenteric
Excludes1
  • chronic or subacute lymphadenitis, except mesenteric (I88.1)
  • enlarged lymph nodes (R59.-)
  • human immunodeficiency virus [HIV] disease resulting in generalized lymphadenopathy (B20)
  • lymphadenitis NOS (I88.9)
  • nonspecific mesenteric lymphadenitis (I88.0)

Broader instructions also apply from L00-L08 Infections of the skin and subcutaneous tissue and Chapter 12: Diseases of the skin and subcutaneous tissue.

Alphabetic index entries

5 entries

Terms in the official ICD-10-CM index that lead to L04.1.

Codes whose notes reference L04.1

MS-DRG v44.0 grouping

All DRGs →

Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.

MDC 15 · Newborns and Other Neonates with Conditions Originating in the Perinatal Period

MDC 15 · Newborns and Other Neonates with Conditions Originating in the Perinatal Period

ICD-9-CM equivalent

Converter →
  • 683Acute lymphadenitisapproximate

From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about L04.1

Is L04.1 billable?

Yes. L04.1 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can L04.1 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict L04.1 as a principal diagnosis.

Is L04.1 a CC or MCC?

No. L04.1 is neither a CC nor an MCC under MS-DRG v44.0.

What DRG does L04.1 group to?

L04.1 is used in the MS-DRG v44.0 logic for MS-DRG 791 (Prematurity with Major Problems), MS-DRG 793 (Full Term Neonate with Major Problems), MS-DRG 814 (Reticuloendothelial and Immunity Disorders with MCC), MS-DRG 815 (Reticuloendothelial and Immunity Disorders with CC) and MS-DRG 816 (Reticuloendothelial and Immunity Disorders without CC/MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.

What is the ICD-9 code for L04.1?

The CMS General Equivalence Mappings map L04.1 to ICD-9-CM 683.