A43

Non-Billable

ChapterA00–B99

Rankcategory

Official Description

Nocardiosis

Metadata & Insights

•2026 ICD-10-CM Edition - Effective October 1, 2025.
•Non-billable category (requires more specific sub-code).
•Chapter 1: Certain Infectious and Parasitic Diseases (A00-B99).

CH1 Parent Instructions

Includes

diseases generally recognized as communicable or transmissible

Excludes1(Not coded here)

certain localized infections - see body system-related chapters

Excludes2(Not included here)

carrier or suspected carrier of infectious disease (Z22.-)
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)

Use Additional Code

code to identify resistance to antimicrobial drugs (Z16.-)

Clinical Hierarchy

CH1Certain infectious and parasitic diseases (A00-B99)

A30-A49Other bacterial diseases (A30-A49)

A43Nocardiosis

A43.0Pulmonary nocardiosis

A43.1Cutaneous nocardiosis

A43.8Other forms of nocardiosis

A43.9Nocardiosis, unspecified

Applicable Ancestor Context

The following parent sections contain instructions or notes that apply to A43:

chapterCH1

Certain infectious and parasitic diseases (A00-B99)

View context instructions

Alphabetic Index Mentions

These are Diagnosis Index lookup paths that route to A43. Use them as entry terms for search, then confirm final coding instructions in the Tabular List and notes above.

7 raw paths

Nocardiosis, nocardiasis6 unique routes

Direct index entry→A43

cutaneous→A43

lung→A43

pneumonia→A43

pulmonary→A43

specified site NEC→A43

Pneumonia (acute) (double) (migratory) (purulent) (septic) (unresolved)1 unique routes

in (due to)

nocardiosis, nocardiasis→A43

MS-DRG Classification

2026

No direct MS-DRG triggers identified.

Cross Reference

Find Procedures (ICD-10-PCS)

Find surgical and procedural codes related to Nocardiosis.

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