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A43.0

A43.0Pulmonary nocardiosis

Billable / specific codeICD-10-CM

A43.0 is a billable, specific ICD-10-CM code for pulmonary nocardiosis. It is valid for submission on a claim.

Other codes that can never be billed with A43.0

These codes carry an Excludes1 note pointing at A43.0. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading A43.0 alone.

  • J17Pneumonia in diseases classified elsewhere

Risk adjustment

A43.0 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

A43.0 is named in 4 Medicare coverage policies 4 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

  • A56580Billing and Coding: Computerized Axial Tomography (CT), Thorax
  • A56717Billing and Coding: Respiratory Therapy (Respiratory Care)
  • A57205Billing and Coding: Oximetry Services
  • A57224Billing and Coding: Respiratory Care

How A43.0 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 A43.0.

  • Nocardiosis, nocardiasislung
  • Nocardiosis, nocardiasispneumonia
  • Nocardiosis, nocardiasispulmonary
  • Pneumoniainnocardiosis, nocardiasis

Related codes at this level

Codes that share A43. If A43.0 is not quite right, the correct code is usually one of these.

Questions about A43.0

Is A43.0 a billable ICD-10-CM code?
Yes. A43.0 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does A43.0 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.