ICD-10-CM Diagnosis Code B99.9 - Unspecified infectious disease (original) (raw)

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ICD List 2025-2026 Edition

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Unspecified infectious disease

ICD-10-CM Code:

B99.9

ICD-10 Code for:

Unspecified infectious disease

Is Billable?

Yes - Valid for Submission

Chronic Condition Indicator: [1]

Not chronic

Code Navigator:

B99.9 is a billable diagnosis code used to specify a medical diagnosis of unspecified infectious disease. The code is valid during the current fiscal year for the submission of HIPAA-covered transactions from October 01, 2025 through September 30, 2026.

Unspecified diagnosis codes like B99.9 are acceptable when clinical information is unknown or not available about a particular condition. Although a more specific code is preferable, unspecified codes should be used when such codes most accurately reflect what is known about a patient's condition. Specific diagnosis codes should not be used if not supported by the patient's medical record.

  1. Code Information
  2. Approximate Synonyms
  3. Clinical Classification
  4. Clinical Information
  5. Tabular List of Diseases and Injuries
  6. Index to Diseases and Injuries References
  8. Diagnostic Related Groups Mapping
  9. Convert to ICD-9 Code
  10. Patient Education
  11. Other Codes Used Similar Conditions
  12. Code History

The following list of clinical terms are approximate synonyms, alternative descriptions, or common phrases that might be used by patients, healthcare providers, or medical coders to describe the same condition. These synonyms and related diagnosis terms are often used when searching for an ICD-10 code, especially when the exact medical terminology is unclear. Whether you're looking for lay terms, similar diagnosis names, or common language alternatives, this list can help guide you to the correct ICD-10 classification.

Clinical Classifications group individual ICD-10-CM diagnosis codes into broader, clinically meaningful categories. These categories help simplify complex data by organizing related conditions under common clinical themes.

They are especially useful for data analysis, reporting, and clinical decision-making. Even when diagnosis codes differ, similar conditions can be grouped together based on their clinical relevance. Each category is assigned a unique CCSR code that represents a specific clinical concept, often tied to a body system or medical specialty.

CCSR Code: INF009

Inpatient Default: Y - Yes, default inpatient assignment for principal diagnosis or first-listed diagnosis.

Outpatient Default: Y - Yes, default outpatient assignment for principal diagnosis or first-listed diagnosis.

infection which lasts for a long period with continuous display of clinical features. persistent infection arises due to inability of host cells to clear primary infections completely. when persistent infections are cleared so that infection symptoms are under control they are often referred to as chronic infections. latent infections are infections in which manifestation of clinical symptoms appear later.

any infection which a patient contracts in a health-care institution.

wheals (urticaria) and/or angioedema presented with daily symptoms lasting for more than 6 weeks. it may be classified into chronic spontaneous and chronic inducible urticaria depending on whether a specific trigger can be linked to the development of vascular reaction.

tumor-like sterile accumulation of serum in a tissue, organ, or cavity. it results from a tissue insult and is the product of tissue inflammation. it most commonly occurs following mastectomy.

delayed infection of the host by a dormant or inactive pathogen.

surgical procedure to remove one or both breasts.

an infection that exhibits features or characteristics that exceed an agreed-upon threshold among subject matter experts, which warrants attention or treatment.

a disorder resulting from the presence and activity of a microbial, viral, fungal, or parasitic agent. it can be transmitted by direct or indirect contact.

infection associated with no detectable symptoms but caused by microorganisms capable of producing easily recognizable diseases, such a poliomyelitis or mumps.

symptomatic; simple aspiration indicated

symptomatic, elective invasive intervention indicated

a finding of leakage due to breakdown of an anastomosis (surgical connection of two separate anatomic structures) in the small bowel.

asymptomatic; clinical or diagnostic observations only; intervention not indicated

excessive granulation tissue at the base of the umbilicus after separation.

prosthetic valve endocarditis that occurs days to weeks after surgery.

prosthetic valve endocarditis that occurs several months to years following valve replacement.

endocarditis occurring on parts of a valve prosthesis or a reconstructed heart valve; it can be classified into early and late prosthetic valve endocarditis.

inflammation of the lacrimal sac in a newborn due to blocked drainage of tears or infection.

inflammation of the umbilical cord stump in newborns.

sudden onset pyelonephritis.

asymptomatic; clinical or diagnostic observations only; intervention not indicated

symptomatic; simple aspiration indicated

symptomatic, elective invasive intervention indicated

a collection of serum in the body.

a finding of tumor-like collection of serum in the tissues.

evidence of acute and subacute endocarditis.

acute inflammation of the endocardium. bacteria is the usual etiologic agent, and the distinction between "acute" and "subacute" has traditionally been made based on the pathogenic organism and clinical presentation.

References found for this diagnosis code in the External Cause of Injuries Index:

Below are the ICD-9 codes that most closely match this ICD-10 code, based on the General Equivalence Mappings (GEMs). This ICD-10 to ICD-9 crosswalk tool is helpful for coders who need to reference legacy diagnosis codes for audits, historical claims, or approximate code comparisons.

ICD-9-CM: 136.9

Approximate Flag - The approximate mapping means this ICD-10 code does not have an exact ICD-9 equivalent. The matched code is the closest available option, but it may not fully capture the original diagnosis or clinical intent.

Infectious Diseases

What are infectious diseases?

Germs, or microbes, are found everywhere - in the air, soil, and water. There are also germs on your skin and in your body. Many of them are harmless, and some can even be helpful. But some of them can make you sick. Infectious diseases are diseases that are caused by germs.

What are the different types of germs that cause infectious diseases?

There are four main types of germs:

How can you get infectious diseases?

There are many different ways that you can get an infectious disease, depending on the type of germ. They can include:

What are the symptoms of infectious diseases?

Infectious diseases can cause many different symptoms. Some are so mild that you may not even notice any symptoms, while others can be life-threatening.

What are the treatments for infectious diseases?

There are treatments for some infectious diseases, such as antibiotic, antiviral, antifungal and anti-parasitic medicines. But for other infections, such as some caused by viruses, you can only treat your symptoms while you wait for your immune system to fight off the germ.

Can infectious diseases be prevented?

You can take steps to help prevent many infectious diseases:

[Learn More in MedlinePlus]