Pulmonary embolism (PE) is a serious condition that occurs when a blood clot gets lodged in a pulmonary artery, blocking blood flow to the lungs. Accurate diagnosis and coding are critical for effective treatment and healthcare management. In the International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM), the diagnosis code I26.99 is used to classify “Other pulmonary embolism without acute cor pulmonale.” This article delves into the details of ICD-10-CM code I26.99, providing a comprehensive understanding for healthcare professionals and anyone seeking information on diagnosis codes for pulmonary embolism.
What is ICD-10-CM Code I26.99?
ICD-10-CM code I26.99 is a billable and specific diagnosis code used in the United States to indicate a diagnosis of “Other pulmonary embolism without acute cor pulmonale” for reimbursement purposes. This code is part of the 2025 ICD-10-CM edition, becoming effective on October 1, 2024. It’s important to note that this is the American version, and other international versions of ICD-10 code I26.99 might differ.
The code I26.99 is applicable to several conditions, including:
- Acute pulmonary embolism NOS (Not Otherwise Specified): This refers to a sudden pulmonary embolism where further specifics are not mentioned.
- Other thrombotic pulmonary embolism without acute cor pulmonale: This includes pulmonary embolisms caused by thrombi (blood clots) that are not specified elsewhere and do not involve acute cor pulmonale (right heart failure due to lung disease).
- Pulmonary embolism NOS: Similar to acute pulmonary embolism NOS, this is a general classification for pulmonary embolism when no further details are provided.
ICD-10-CM diagnosis code I26.99 for pulmonary embolism, the US version, is effective from October 1, 2024.
Understanding Pulmonary Embolism
To fully grasp the significance of diagnosis code I26.99, it’s crucial to understand pulmonary embolism itself.
Definition and Causes
Pulmonary embolism is defined as the blockage of a pulmonary artery in the lungs. This blockage is most often caused by a blood clot that travels from another part of the body, most commonly from a deep vein thrombosis (DVT) in the legs. When this clot breaks free, it travels through the bloodstream to the lungs and can lodge in a pulmonary artery, obstructing blood flow.
Symptoms
Pulmonary embolism can be a subtle condition, with approximately half of individuals experiencing it showing no noticeable symptoms. However, when symptoms do appear, they can include:
- Shortness of breath: This is often sudden and unexplained.
- Chest pain: May feel like a heart attack, sharp, and worsens with deep breaths.
- Coughing up blood: Hemoptysis, coughing up blood or blood-streaked mucus.
- Symptoms of a blood clot (usually in the leg): These can include warmth, swelling, pain, tenderness, and redness in the affected leg.
The severity of symptoms can vary widely depending on the size and location of the clot, as well as the individual’s overall health.
Clinical Significance
Pulmonary embolism is a serious medical condition with potentially life-threatening consequences. It can lead to:
- Permanent damage to the affected lung: Reduced lung function and chronic breathing problems.
- Low oxygen levels in the blood (hypoxemia): Insufficient oxygen supply to the body’s tissues.
- Damage to other organs: Organ damage due to lack of oxygen.
- Death: Large or multiple clots can be fatal.
Prompt diagnosis and treatment are essential to minimize these risks and improve patient outcomes.
Related Terms and Synonyms
Understanding related terms can help clarify the scope of diagnosis code I26.99. The original ICD-10-CM documentation lists “Approximate Synonyms” for I26.99, which include:
- Acute pulmonary embolism: A sudden onset pulmonary embolism.
- Iatrogenic pulmonary embolism with infarction: Pulmonary embolism caused by medical intervention, leading to tissue death (infarction) in the lung.
- Infarction of lung due to iatrogenic pulmonary embolism: Similar to the above, emphasizing the lung infarction as a result of iatrogenic PE.
- Pulmonary embolism: General term for the condition.
- Pulmonary embolism (blood clot in lung): A layperson’s term clarifying the cause of PE.
- Pulmonary embolism and infarction, iatrogenic: Combining both PE and infarction with an iatrogenic cause.
- Pulmonary embolism with infarction: PE that has resulted in lung tissue infarction.
- Pulmonary embolism with pulmonary infarction: Another way to describe PE with lung infarction.
Additionally, the concept of “Annotation Back-References” is mentioned. In the context of ICD-10-CM, these are codes that have annotations (notes, inclusions, exclusions, etc.) that might be relevant to I26.99, providing further context and guidance for accurate coding.
ICD-10-CM Code History and Grouping
ICD-10-CM code I26.99 is a relatively recent addition to the classification system. It was introduced in 2016 (effective October 1, 2015) and has remained unchanged through the 2025 edition. This stability indicates its established role in medical coding and diagnosis.
Furthermore, ICD-10-CM I26.99 is grouped within Diagnostic Related Groups (MS-DRG v42.0). MS-DRGs are a system used to classify hospital cases and determine payments, reflecting the clinical complexity and resource utilization associated with different diagnoses.
Related ICD-10-CM Codes
For a broader understanding, it’s helpful to consider codes adjacent to I26.99 in the ICD-10-CM manual. These include codes for:
- I26.03 Cement embolism of pulmonary artery with acute cor pulmonale
- I26.04 Fat embolism of pulmonary artery with acute cor pulmonale
- I26.09 Other pulmonary embolism with acute cor pulmonale
- I26.9 Pulmonary embolism without acute cor pulmonale (parent category)
- I26.90 Septic pulmonary embolism without acute cor pulmonale
- I26.92 Saddle embolus of pulmonary artery without acute cor pulmonale
- I26.93 Single subsegmental thrombotic pulmonary embolism without acute cor pulmonale
- I26.94 Multiple subsegmental thrombotic pulmonary emboli without acute cor pulmonale
- I26.95 Cement embolism of pulmonary artery without acute cor pulmonale
- I26.96 Fat embolism of pulmonary artery without acute cor pulmonale
- I27 Other pulmonary heart diseases (broader category)
These adjacent codes highlight the specificity within the pulmonary embolism classification, differentiating based on the presence of acute cor pulmonale, the type of embolus (cement, fat, septic), and the location/extent of the embolism (saddle, subsegmental).
Conclusion
Diagnosis code I26.99 is a vital tool for classifying and coding “Other pulmonary embolism without acute cor pulmonale” within the ICD-10-CM system. Understanding this code, along with the broader context of pulmonary embolism, its symptoms, and related codes, is essential for healthcare professionals involved in diagnosis, treatment, and medical billing. Accurate coding ensures appropriate reimbursement and contributes to valuable data collection for epidemiological studies and healthcare quality improvement related to this serious condition.
