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L43.2 ICD-10-CM Code: Lichenoid drug reaction

Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Coding at a Glance

Tabular directives
1 Excludes1 · 1 use-additional code

Inpatient Payment Groups (MS-DRG)

Potential MS-DRG participation — not a DRG assignment.

MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v43, Appendix B.

  • MS-DRG 606 — MINOR SKIN DISORDERS WITH MCC (MDC 09)
  • MS-DRG 607 — MINOR SKIN DISORDERS WITHOUT MCC (MDC 09)

A diagnosis appearing in a group's logic does not by itself determine the DRG assigned to a stay; the grouper uses the full claim.

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for L43.2 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2026Effective: October 1, 2025

Notes without a marker are published on L43.2 itself; “inherited from” names the category or block whose note applies here.

Excludes1 — Not Coded Here

Conditions generally not reported together with this code (Excludes1) -- an error unless the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

Source: inherited from L43

Use Additional Code

Supplementary codes the tabular list directs you to add.

  • Use additional code for adverse effect, if applicable, to identify drug (T36-T50 with fifth or sixth character 5)

Coder workflow for L43.2

MedCoder structured workflow — derived from this code’s own official record

Before you code L43.2

  1. Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with L43.2. Excludes1 conditions are not reported together with this code unless the record shows they are unrelated (Guidelines I.A.12.a).

    See the official tabular notes

Choose the right path

  1. Does the documentation support a condition named in L43.2’s Excludes1 note?
    Yes → Do not simply proceed: review the excluded code. Both are reported only when the record shows the two conditions are unrelated.
    No → Continue.

    ReviewL66.1

Consider L43.2. Then work the Use Additional Code note, and confirm the code is valid for the date of service in the Verify section.

Documentation check

The provider’s diagnostic statement
Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).
The conditions the Use Additional Code note names
Reported with this code when documented; a conditional instruction (“if applicable”, “if known”) applies only when the record supports it.

Official instructions as workflow

  • Excludes1 — check before selecting L43.2(1 note)

    Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with L43.2: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.

    CompareL66.1

    See the official tabular notes · Guidelines I.A.12.a

  • Use Additional Code — after identifying L43.2(1 note)

    Coding workflow: Check whether the documentation supports the additional code(s) the note names, and report them with L43.2 when it does. Where the instruction is conditional (“if applicable”, “if known”), it applies only when the record documents the condition.

    See the official tabular notes · Guidelines I.A.13

Coding decision scenarios

Pattern scenarios for this code’s structure — decision rules, not clinical cases

Documentation: Both the condition L43.2 describes and a condition named in its Excludes1 note are documented for the same encounter.

Coding question: Can both codes be reported?

Path: Review the Excludes1 note and the excluded code, and look for a provider statement on whether the two conditions are related.

Reason: Excludes1 means the two are not coded together; the exception is when the record shows the conditions are unrelated to each other (Guidelines I.A.12.a).

ReviewL66.1

Documentation: A condition the Use Additional Code note names is documented.

Coding question: Is a second code reported with L43.2?

Path: Review the Use Additional Code note and the code it names.

Reason: The additional code is reported when the record documents the condition; a conditional instruction applies only when its condition is met (Guidelines I.A.13).

Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.

Code Overview

Lichenoid drug reaction is a billable ICD-10-CM diagnosis code (L43.2).

MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.

Indexed Clinical Terms (1)

Official source data — entries quoted as published, in the Index’s own lookup phrasing

Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code. These are alphabetic-index entries shown as the Index writes them — lookup phrasing, not necessarily the wording of a final diagnosis.

Verify Before Coding

  • No Medicare Code Editor or MS-DRG Definitions Manual restrictions apply to this code.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

MedCoder structured relationships — computed from published CMS and AHRQ datasets

MS-DRG Grouper Relationships (FY2026)

Potential MS-DRG participation — not a DRG assignment.

FY2026 MS-DRG: not on the CMS CC/MCC list — as a secondary diagnosis this code does not change MS-DRG severity for that release.

Named in the grouper logic of 2 MS-DRGs: DRG 606 (MDC 09), DRG 607 (MDC 09).

From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.

Clinical classification (AHRQ CCSR):SKN002 — Other specified inflammatory condition of skin (default); INJ030 — Drug induced or toxic related condition.

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Related Codes

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical categories (Other specified inflammatory condition of skin, Drug induced or toxic related condition).

L41.0 — Pityriasis lichenoides et varioliformis acuta, L41.1 — Pityriasis lichenoides chronica, L41.3 — Small plaque parapsoriasis, L41.4 — Large plaque parapsoriasis, L41.5 — Retiform parapsoriasis, L41.8 — Other parapsoriasis, L41.9 — Parapsoriasis, unspecified, L42 — Pityriasis rosea, L43.0 — Hypertrophic lichen planus, L43.1 — Bullous lichen planus, L43.3 — Subacute (active) lichen planus, L43.8 — Other lichen planus, L43.9 — Lichen planus, unspecified, L44.0 — Pityriasis rubra pilaris, L44.1 — Lichen nitidus, L44.2 — Lichen striatus, L44.3 — Lichen ruber moniliformis, L44.4 — Infantile papular acrodermatitis [Gianotti-Crosti], L44.8 — Other specified papulosquamous disorders, L44.9 — Papulosquamous disorder, unspecified, +390 more

Same Index main term, other category

The ICD-10-CM Index to Diseases and Injuries files this code under the main term “Reaction”; these codes share that main term but sit in a different category of the Tabular List.

F44.9 — Dissociative and conversion disorder, unspecified (hysterical), F45.20 — Hypochondriacal disorder, unspecified (hypochondriacal), F48.1 — Depersonalization-derealization syndrome (psychoneurotic, depersonalization), F48.8 — Other specified nonpsychotic mental disorders (asthenic), F48.9 — Nonpsychotic mental disorder, unspecified (neurotic), F60.7 — Dependent personality disorder (passive dependency), F93.8 — Other childhood emotional disorders (fear, child), F94.0 — Selective mutism (adjustment, with, mutism, elective), F99 — Mental disorder, not otherwise specified (psychogenic), G97.1 — Other reaction to spinal and lumbar puncture (lumbar puncture), L56.0 — Drug phototoxic response (drug NEC, phototoxic), L56.1 — Drug photoallergic response (drug NEC, photoallergic), O29.3X — Toxic reaction to local anesthesia during pregnancy (toxic, to local anesthesia, in pregnancy), O74.4 — Toxic reaction to local anesthesia during labor and delivery (toxic, to local anesthesia, in labor and delivery), O89.3 — Toxic reaction to local anesthesia during the puerperium (toxic, to local anesthesia, postpartum, puerperal), P93.0 — Grey baby syndrome (drug NEC, newborn, gray baby syndrome), P93.8 — Other reactions and intoxications due to drugs administered to newborn (drug NEC, newborn), P96.1 — Neonatal withdrawal symptoms from maternal use of drugs of addiction (drug NEC, withdrawal, newborn), R50.84 — Febrile nonhemolytic transfusion reaction (febrile nonhemolytic transfusion), R68.89 — Other general symptoms and signs (Herxheimer's), +36 more

Contextual Map

Every relationship of L43.2 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Run L43.2 with these 8 related codes in Claim Check

Hierarchy

Use Additional Code (15)

Clinical classification (CCSR)

MS-DRG Grouper

MDC crossing

  • MDC 09 — Diseases and Disorders of the Skin, Subcutaneous Tissue and Breast[MDC crossing]: “Diseases and Disorders of the Skin, Subcutaneous Tissue and Breast — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs. 7,376 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2026

Index entries

  • Reaction, drug NEC, lichenoid[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026

Nearest codes

Change history

  • FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data
CMS/CDC ICD-10-CM FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v43.1 (April 2026) Release, file and checksum · Publisher’s page
Inpatient payment groups Official source data
CMS MS-DRG Definitions Manual (incl. Appendix B diagnosis index, Appendix C CC/MCC list, Appendix E procedure index) and IPPS Final Rule tables — v43 Release, file and checksum · Publisher’s page
Change history and date-of-service validity Official source data
CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page
Comparisons, relationships and the contextual map MedCoder structured relationship
Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears
Summary and FAQ answers MedCoder explanation
Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates

Cite this page

Reference this page in a research guide, syllabus or article. The release is included because code content changes each year.

MedCoder.ai. "L43.2 — Lichenoid drug reaction." ICD-10-CM FY2026. https://medcoder.ai/icd10/code/l43.2-lichenoid-drug-reaction

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Lichenoid drug reaction

No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027 (effective October 1, 2026), and none are recorded for this code. Note changes are tracked from FY2027 only.

Nearest Codes in This Family

Official ICD-10-CM classifications closest to L43.2 in its code family, with their registry titles.

View all codes in the L43 family