J22 Unspecified acute lower respiratory infection

The ICD-10-CM code for Unspecified acute lower respiratory infection is J22 (FY2026). It is a billable, claim-ready diagnosis code.

Classification

Chapter

10: Diseases of the respiratory system (J00-J99)

Section

J20-J22: Other acute lower respiratory infections (J20-J22)

Category J22

1 code (1 billable)

FY2026 Status

Stable since FY2024

Also Known As

ICD-10-CM Alphabetic Index entries that lead to J22:

• Infection, infected, infective (opportunistic) › chest
• Infection, infected, infective (opportunistic) › respiratory (tract) NEC › lower (acute)
• Infection, infected, infective (opportunistic) › respiratory (tract) NEC › acute

Inclusion Terms

• Acute (lower) respiratory (tract) infection NOS

U.S. Hospital Utilization

• An estimated 7,775 U.S. inpatient stays in 2023 included J22 among the documented diagnoses.
• 1,130 stays listed it as the principal diagnosis.

Source: National Inpatient Sample (NIS), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality, 2016–2023. National survey-weighted estimates.

Official Coding Guidelines

Lower respiratory infection NOS/acute respiratory infection NOS—U07.1 + J22

(iii)Lower respiratory infection If the COVID-19 is documented as being associated with a lower respiratory infection, not otherwise specified (NOS), or an acute respiratory infection, NOS, codes U07.1 and J22, Unspecified acute lower respiratory infection, should be assigned.

COPD/asthma: acute exacerbation vs uncomplicated

a. Chronic Obstructive Pulmonary Disease [COPD] and Asthma 1) Acute exacerbation of chronic obstructive bronchitis and asthma The codes in categories J44 and J45 distinguish between uncomplicated cases and those in acute exacerbation. An acute exacerbation is a worsening or a decompensation of a chronic condition. An acute exacerbation is not equivalent to an infection superimposed on a chronic condition, though an exacerbation may be triggered by an infection.

Source: CMS — ICD-10-CM Official Guidelines for Coding and Reporting, FY2026

References

• CMS — ICD-10-CM Official Code Set and Guidelines, FY2026
• CDC/NCHS — ICD-10-CM Files and Browser Tool
• AHRQ — HCUP National Inpatient Sample, Frequencies by Diagnosis Code (2016–2023)