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A48.1

A48.1Legionnaires' disease

Billable / specific codeICD-10-CM

A48.1 is a billable, specific ICD-10-CM code for legionnaires' disease. It is valid for submission on a claim.

Other codes that can never be billed with A48.1

These codes carry an Excludes1 note pointing at A48.1. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading A48.1 alone.

  • J15Bacterial pneumonia, not elsewhere classified

Risk adjustment

A48.1 risk-adjusts. Under the CMS-HCC V28 model it maps to this category:

  • HCC 282 Aspiration and Specified Bacterial Pneumonias0.440 RAF

Coefficient shown for the Community Non-dual Aged segment. A higher HCC in the same hierarchy will suppress this one, so capturing it does not always add score.

Medicare coverage

A48.1 is named in 12 Medicare coverage policies 12 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

  • A52466Nebulizers - Policy Article
  • A52466Nebulizers - Policy Article
  • A52466Nebulizers - Policy Article
  • A52466Nebulizers - Policy Article

How A48.1 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 A48.1.

  • Legionellosis
  • Disease, diseasedlegionnaires'
  • Infection, infected, infectiveLegionella pneumophila
  • Legionnaires'disease
  • Legionnaires'pneumonia

Related codes at this level

Codes that share A48. If A48.1 is not quite right, the correct code is usually one of these.

Questions about A48.1

Is A48.1 a billable ICD-10-CM code?
Yes. A48.1 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does A48.1 sit in the tabular list?
Certain infectious and parasitic diseases (A00-B99), in the block Other bacterial diseases (A30-A49).
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.