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A55

A55Chlamydial lymphogranuloma (venereum)

Billable / specific codeICD-10-CM

A55 is a billable, specific ICD-10-CM code for chlamydial lymphogranuloma (venereum). It is valid for submission on a claim.

Inclusion terms

Alternative wordings a physician may use in the chart for this same code.

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

Other codes that can never be billed with A55

These codes carry an Excludes1 note pointing at A55. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading A55 alone.

  • A74Other diseases caused by chlamydiae

Risk adjustment

A55 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

Medicare coverage

A55 is named in 2 Medicare coverage policies 2 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

  • A56456Billing and Coding: Colonoscopy/Sigmoidoscopy/Proctosigmoidoscopy
  • A56632Billing and Coding: Colonoscopy/Sigmoidoscopy/Proctosigmoidoscopy

How A55 is indexed

Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to A55.

  • Durand-Nicolas-Favre disease
  • Esthiomene
  • Frei's disease
  • Genito-anorectal syndrome
  • Lymphopathia venereum, veneris
  • Nicolas-Favre disease(-Durand)
  • Poradenitis, nostras inguinalis or venerea
  • Buboclimatic
  • Bubotropical
  • Disease, diseasedDurand-Nicholas-Favre(climatic bubo)
  • Disease, diseasedFavre-Durand-Nicolas(climatic bubo)
  • Disease, diseasedFrei's(climatic bubo)

Questions about A55

Is A55 a billable ICD-10-CM code?
Yes. A55 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does A55 sit in the tabular list?
Certain infectious and parasitic diseases (A00-B99), in the block Infections with a predominantly sexual mode of transmission (A50-A64).
ICD-10-CMFY2026-Apr· effective April 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release — see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.