Pneumonia, unspecified organism (J18)

ICD-10 code J18 and its subcodes are used to classify different forms of pneumonia where the exact causative organism is not identified. These codes cover a variety of pneumonia types, including bronchopneumonia, lobar pneumonia, hypostatic pneumonia, and other unspecified pneumonias.

The ICD-10 code for pneumonia, unspecified organism (J18) and its detailed categories help medical professionals document cases without specific microbial diagnosis. For example, J18.0 represents bronchopneumonia, which may also be known by synonyms like acute bronchopneumonia or hemorrhagic bronchopneumonia, while J18.1 is for lobar pneumonia, covering terms like basal pneumonia or lung consolidation. J18.2 refers to hypostatic pneumonia, sometimes called hypostatic bronchopneumonia. Codes like J18.8 and J18.9 capture other unspecified pneumonia types, including chronic or atypical pneumonia, making these codes essential for documenting pneumonia cases when pathogen identification is not possible. Using these codes ensures precise diagnosis coding for billing and epidemiological tracking when the pneumonia cause remains unknown.

Instructional Notations

Code First

Certain conditions have both an underlying etiology and multiple body system manifestations due to the underlying etiology. For such conditions, the ICD-10-CM has a coding convention that requires the underlying condition be sequenced first followed by the manifestation. Wherever such a combination exists, there is a "use additional code" note at the etiology code, and a "code first" note at the manifestation code. These instructional notes indicate the proper sequencing order of the codes, etiology followed by manifestation.

Code Also

A "code also" note instructs that two codes may be required to fully describe a condition, but this note does not provide sequencing direction.

  • , if applicable, any associated condition such as:
  • aspiration pneumonia J69

Type 1 Excludes

A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.

  • 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

Type 2 Excludes

A type 2 excludes note represents "Not included here". An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.

  • 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

Clinical Terms

The following clinical terms provide additional context, helping users better understand the clinical background and common associations for each diagnosis listed in this section. Including related terms alongside ICD-10-CM codes supports coders, billers, and healthcare professionals in improving accuracy, enhancing documentation, and facilitating research or patient education.

Bronchopneumonia

Inflammation of the lung parenchyma that is associated with BRONCHITIS, usually involving lobular areas from TERMINAL BRONCHIOLES to the PULMONARY ALVEOLI. The affected areas become filled with exudate that forms consolidated patches.

Chlamydial Pneumonia

Pneumonia caused by infections with the genus CHLAMYDIA; and CHLAMYDOPHILA, usually with CHLAMYDOPHILA PNEUMONIAE.

Community-Acquired Pneumonia

Infection of the lungs in a patient who is not hospitalized or who has not resided in a long-term care facility for 14 days prior to the onset of symptoms. It is associated with some signs and symptoms of acute infection and is accompanied by the presence of an acute infiltrate on chest radiograph.(US Pharm. 2007;32(10):44-5 https://www.uspharmacist.com/article/community-acquired-pneumonia)

Cryptogenic Organizing Pneumonia

An interstitial lung disease of unknown etiology, occurring between 21-80 years of age. It is characterized by a dramatic onset of a pneumonia-like illness with cough, fever, malaise, fatigue, and weight loss. Pathological features include prominent interstitial inflammation without collagen fibrosis, diffuse fibroblastic foci, and no microscopic honeycomb change. There is excessive proliferation of granulation tissue within small airways and alveolar ducts.

Eosinophils

Granular leukocytes with a nucleus that usually has two lobes connected by a slender thread of chromatin, and cytoplasm containing coarse, round granules that are uniform in size and stainable by eosin.

Hamman-Rich Syndrome

Acute idiopathic interstitial pneumonitis characterized by diffuse PULMONARY ALVEOLI damage with uniform edematous connective tissue proliferation. It is often associated with extensive fibroblastic distortion of the lung parenchyma and leads to ADULT RESPIRATORY DISTRESS SYNDROME in later stages.

Healthcare-Associated Pneumonia

Infection of the lung often accompanied by inflammation that is acquired through an interaction within a healthcare institution often through a therapeutic experience (e.g., use of catheters or ventilators).

Idiopathic Interstitial Pneumonias

A group of interstitial lung diseases with no known etiology. There are several entities with varying patterns of inflammation and fibrosis. They are classified by their distinct clinical-radiological-pathological features and prognosis. They include IDIOPATHIC PULMONARY FIBROSIS; CRYPTOGENIC ORGANIZING PNEUMONIA; and others.

Lung Diseases, Interstitial

A diverse group of lung diseases that affect the lung parenchyma. They are characterized by an initial inflammation of PULMONARY ALVEOLI that extends to the interstitium and beyond leading to diffuse PULMONARY FIBROSIS. Interstitial lung diseases are classified by their etiology (known or unknown causes), and radiological-pathological features.

Murine pneumonia virus

A species of the genus PNEUMOVIRUS causing pneumonia in mice.

Organizing Pneumonia

Any obstructive lung disease characterized by consolidated formation of GRANULATION TISSUE polyps within ALVEOLAR DUCTS AND ALVEOLI. It is classified as either primary (cryptogenic organizing pneumonia) or secondary organizing pneumonia. Secondary organizing pneumonia after transplantation is called bronchiolitis obliterans syndrome.

Pneumonia

Infection of the lung often accompanied by inflammation.

Pneumonia of Calves, Enzootic

Chronic endemic respiratory disease of dairy calves and an important component of bovine respiratory disease complex. It primarily affects calves up to six months of age and the etiology is multifactorial. Stress plus a primary viral infection is followed by a secondary bacterial infection. The latter is most commonly associated with PASTEURELLA MULTOCIDA producing a purulent BRONCHOPNEUMONIA. Sometimes present are MANNHEIMIA HAEMOLYTICA; HAEMOPHILUS SOMNUS and mycoplasma species.

Pneumonia of Swine, Mycoplasmal

A chronic, clinically mild, infectious pneumonia of PIGS caused by MYCOPLASMA HYOPNEUMONIAE. Ninety percent of swine herds worldwide are infected with this economically costly disease that primarily affects animals aged two to six months old. The disease can be associated with porcine respiratory disease complex. PASTEURELLA MULTOCIDA is often found as a secondary infection.

Pneumonia, Aspiration

A type of lung inflammation resulting from the aspiration of food, liquid, or gastric contents into the upper RESPIRATORY TRACT.

Pneumonia, Atypical Interstitial, of Cattle

A cattle disease of uncertain cause, probably an allergic reaction.

Pneumonia, Bacterial

Inflammation of the lung parenchyma that is caused by bacterial infections.

Pneumonia, Lipid

Pneumonia due to aspiration or inhalation of various oily or fatty substances or otherwise accumulation of endogenous lipid substances in the PULMONARY ALVEOLI.

Pneumonia, Mycoplasma

Interstitial pneumonia caused by extensive infection of the lungs (LUNG) and BRONCHI, particularly the lower lobes of the lungs, by MYCOPLASMA PNEUMONIAE in humans. In SHEEP, it is caused by MYCOPLASMA OVIPNEUMONIAE. In CATTLE, it may be caused by MYCOPLASMA DISPAR.

Pneumonia, Necrotizing

Severe complication of pneumonia characterized by liquefaction of lung tissue.

Pneumonia, Pneumococcal

A febrile disease caused by STREPTOCOCCUS PNEUMONIAE.

Pneumonia, Pneumocystis

A pulmonary disease in humans occurring in immunodeficient or malnourished patients or infants, characterized by DYSPNEA, tachypnea, and HYPOXEMIA. Pneumocystis pneumonia is a frequently seen opportunistic infection in AIDS. It is caused by the fungus PNEUMOCYSTIS JIROVECII. The disease is also found in other MAMMALS where it is caused by related species of Pneumocystis.

Pneumonia, Progressive Interstitial, of Sheep

Chronic respiratory disease caused by the VISNA-MAEDI VIRUS. It was formerly believed to be identical with jaagsiekte (PULMONARY ADENOMATOSIS, OVINE) but is now recognized as a separate entity.

Pneumonia, Rickettsial

Pneumonia caused by infection with bacteria of the family RICKETTSIACEAE.

Pneumonia, Staphylococcal

Pneumonia caused by infections with bacteria of the genus STAPHYLOCOCCUS, usually with STAPHYLOCOCCUS AUREUS.

Pneumonia, Ventilator-Associated

Serious INFLAMMATION of the LUNG in patients who required the use of PULMONARY VENTILATOR. It is usually caused by bacterial CROSS INFECTION in hospitals.

Pneumonia, Viral

Inflammation of the lung parenchyma that is caused by a viral infection.

Pneumovirus

A genus of the family PARAMYXOVIRIDAE (subfamily PNEUMOVIRINAE) where the human and bovine virions have neither hemagglutinin nor neuraminidase activity. RESPIRATORY SYNCYTIAL VIRUS, HUMAN is the type species.

Pulmonary Alveoli

Small polyhedral outpouchings along the walls of the alveolar sacs, alveolar ducts and terminal bronchioles through the walls of which gas exchange between alveolar air and pulmonary capillary blood takes place.

Pulmonary Eosinophilia

A condition characterized by infiltration of the lung with EOSINOPHILS due to inflammation or other disease processes. Major eosinophilic lung diseases are the eosinophilic pneumonias caused by infections, allergens, or toxic agents.

Radiation Pneumonitis

Inflammation of the lung due to harmful effects of ionizing or non-ionizing radiation.

Rickettsiaceae

A family of gram-negative bacteria belonging to the order Rickettsiales.

Streptococcus pneumoniae

A gram-positive organism found in the upper respiratory tract, inflammatory exudates, and various body fluids of normal and/or diseased humans and, rarely, domestic animals.