A55

Chlamydial lymphogranuloma (venereum)

FY2027Chapter 1: Certain infectious and parasitic diseases/A50–A64 Infections with a predominantly sexual mode of transmission

BillableComplete code, valid to report

A55 is a billable ICD-10-CM diagnosis code for chlamydial lymphogranuloma (venereum). It is part of the FY2027 code set, effective October 1, 2026. The Alphabetic Index lists it under 30 entries. Its coding notes include a Use additional code instruction, 2 Excludes1 entries and 6 Excludes2 entries.

Use additional code

Add the listed code as a secondary code, if known.

Also from chapter/block level (1 note)
Inherited from Chapter 1 Certain infectious and parasitic diseases
  • code to identify resistance to antimicrobial drugs (Z16.-)

Excludes1

Not coded here. The listed conditions generally should not be reported together.

Also from chapter/block level (2 notes)
Inherited from A50–A64 Infections with a predominantly sexual mode of transmission
  • nonspecific and nongonococcal urethritis (N34.1)
  • Reiter's disease (M02.3-)

Excludes2

Not included here. Both codes may be reported if the patient has both conditions.

Also from chapter/block level (6 notes)
Inherited from A50–A64 Infections with a predominantly sexual mode of transmission
  • human immunodeficiency virus [HIV] disease (B20)
Inherited from Chapter 1 Certain infectious and parasitic diseases
  • carrier or suspected carrier of infectious disease (Z22.-)
  • certain localized infections - see body system-related chapters
  • infectious and parasitic diseases complicating pregnancy, childbirth and the puerperium (O98.-)
  • infectious and parasitic diseases specific to the perinatal period (P35-P39)
  • influenza and other acute respiratory infections (J00-J22)

Care settings

How CMS programs treat this code. These are CMS claim edits and list entries, not coverage or eligibility rules.

Home Health Primary

Accepted as the primary (principal) diagnosis on a home health claim. The Home Health Grouper assigns it to the MMTA - Infectious Disease, Neoplasms, and Blood-Forming Diseases clinical group.

Source: CMS Home Health Grouper Software v07.2.26, effective October 1, 2026

Includes

Further defines or gives examples of the content of the category.

Also from chapter/block level (1 note)
Inherited from Chapter 1 Certain infectious and parasitic diseases
  • diseases generally recognized as communicable or transmissible

Inclusion terms

Conditions classified to this code.

This code
  • Climatic or tropical bubo
  • Durand-Nicolas-Favre disease
  • Esthiomene
  • Lymphogranuloma inguinale

Alphabetic Index terms

Terms the official Alphabetic Index lists for this code. 30 entries

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