J18.1 is the authoritative medical code for Lobar pneumonia, unspecified organism. This classification is used in medical billing and clinical recording to specify the clinical criteria for lobar pneumonia, unspecified organism (ICD-10-CM J18.1), ensuring healthcare documentation aligns with 2026 federal coding standards.
Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.
Official Registry Overview & Definition
Lobar pneumonia, unspecified organism is a billable ICD-10-CM diagnosis code J18.1. Excludes1 (not coded here): congenital pneumonia P23.0; drug-induced interstitial lung disorder J70.2-J70.4; interstitial pneumonia NOS J84.9; neonatal aspiration pneumonia P24.-; pneumonitis due to fumes and vapors J68.0; usual interstitial pneumonia J84.178. Excludes2 (not included here): abscess of lung with pneumonia J85.1; aspiration pneumonia due to anesthesia during labor and delivery O74.0; aspiration pneumonia due to anesthesia during pregnancy O29; aspiration pneumonia due to anesthesia during puerperium O89.0; aspiration pneumonia due to solids and liquids J69.-; aspiration pneumonia NOS J69.0; lipid pneumonia J69.1; pneumonitis due to external agents J67-J70; allergic or eosinophilic pneumonia J82; meconium pneumonia P24.01; neonatal aspiration pneumonia P24.-; pneumonia due to solids and liquids J69.-; congenital pneumonia P23.9; rheumatic pneumonia I00; ventilator associated pneumonia J95.851. Code first: , if applicable, associated influenza (J09.X1, J10.0-, J11.0-). Use additional code: code, if applicable, to identify resistance to antimicrobial drugs Z16.-. Code also: , if applicable, any associated condition such as:; aspiration pneumonia J69.-.
Official Tabular Instructional Notes
Sequencing, inclusion, and exclusion notes published for J18.1 in the official ICD-10-CM tabular list.
Excludes1 — Not Coded Here
Conditions that can never be reported with this code; the two are mutually exclusive.
- congenital pneumonia P23.0
- drug-induced interstitial lung disorder J70.2-J70.4
- interstitial pneumonia NOS J84.9
- neonatal aspiration pneumonia P24.-
- pneumonitis due to fumes and vapors J68.0
- usual interstitial pneumonia J84.178
Excludes2 — Not Included Here
Conditions not covered by this code, but which may be reported alongside it when both are present.
- abscess of lung with pneumonia J85.1
- aspiration pneumonia due to anesthesia during labor and delivery O74.0
- aspiration pneumonia due to anesthesia during pregnancy O29
- aspiration pneumonia due to anesthesia during puerperium O89.0
- aspiration pneumonia due to solids and liquids J69.-
- aspiration pneumonia NOS J69.0
- lipid pneumonia J69.1
- pneumonitis due to external agents J67-J70
- allergic or eosinophilic pneumonia J82
- meconium pneumonia P24.01
- neonatal aspiration pneumonia P24.-
- pneumonia due to solids and liquids J69.-
- congenital pneumonia P23.9
- rheumatic pneumonia I00
- ventilator associated pneumonia J95.851
Code First
Underlying conditions that must be sequenced before this code.
- , if applicable, associated influenza (J09.X1, J10.0-, J11.0-)
Code Also
Additional codes that may be required to fully describe the encounter.
- , if applicable, any associated condition such as:
- aspiration pneumonia J69.-
Use Additional Code
Supplementary codes the tabular list directs you to add.
- code, if applicable, to identify resistance to antimicrobial drugs Z16.-
Frequently Asked Questions (FAQ) & Clinical Guidance
What can't be coded together with J18.1?
Per Excludes1 instructions, J18.1 must not be reported with: congenital pneumonia (P23.0); drug-induced interstitial lung disorder (J70.2-J70.4); interstitial pneumonia NOS (J84.9); neonatal aspiration pneumonia (P24.-).
Can J18.1 be reported alongside related conditions?
Per Excludes2 instructions, J18.1 and the following may both be reported when both are present: abscess of lung with pneumonia (J85.1); aspiration pneumonia due to anesthesia during labor and delivery (O74.0); aspiration pneumonia due to anesthesia during pregnancy (O29); aspiration pneumonia due to anesthesia during puerperium (O89.0).
Does J18.1 need to be sequenced after another code?
Yes. Code first: , if applicable, associated influenza (J09.X1, J10.0-, J11.0-).
Is an additional code needed with J18.1?
Use additional code(s) to specify: code, if applicable, to identify resistance to antimicrobial drugs (Z16.-).
Codes in This Family (5)
Official ICD-10-CM classifications in the same code family as J18.1, with their registry titles.
- J18 — Pneumonia, unspecified organism
- J18.0 — Bronchopneumonia, unspecified organism
- J18.2 — Hypostatic pneumonia, unspecified organism
- J18.8 — Other pneumonia, unspecified organism
- J18.9 — Pneumonia, unspecified organism
Indexed Clinical Terms (1)
Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code.
- Pneumonia (acute) (double) (migratory) (purulent) (septic) (unresolved), lobar (disseminated) (double) (interstitial)
Related Codes & Numerical Sequence (Crawl Map)
Search engines and indexers are advised to traverse adjacent medical codes in this sub-chapter range to find correlated diagnoses or therapeutic procedures: