D18.1 Lymphangioma, any site

The ICD-10-CM code for Lymphangioma, any site is D18.1 (FY2026). It is a billable, claim-ready diagnosis code.

Classification

Chapter

2: Neoplasms (C00-D49)

Section

D10-D36: Benign neoplasms, except benign neuroendocrine tumors (D10-D36)

Category D18

8 codes (6 billable)

FY2026 Status

Stable since FY2024

Also Known As

ICD-10-CM Alphabetic Index entries that lead to D18.1:

• Lymphangioma
• Lymphangioendothelioma
• Hygroma (congenital) (cystic)
• Hemolymphangioma
• Lymphangiomyoma
• Cyst (colloid) (mucous) (simple) (retention) › lymphangiomatous
• Lymphangioma › cavernous
• Lymphangioma › capillary

U.S. Hospital Utilization

• An estimated 6,715 U.S. inpatient stays in 2023 included D18.1 among the documented diagnoses.
• 325 stays listed it as the principal diagnosis.

Source: National Inpatient Sample (NIS), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality, 2016–2023. National survey-weighted estimates.

Official Coding Guidelines

Tx of primary site (TOC entry)

a. Admission/Encounter for treatment of primary site ............................................................. 33

Tx of secondary site (TOC entry)

b. Admission/Encounter for treatment of secondary site .......................................................... 33

Source: CMS — ICD-10-CM Official Guidelines for Coding and Reporting, FY2026

References

• CMS — ICD-10-CM Official Code Set and Guidelines, FY2026
• CDC/NCHS — ICD-10-CM Files and Browser Tool
• AHRQ — HCUP National Inpatient Sample, Frequencies by Diagnosis Code (2016–2023)