Communicating the Difference Between Quarantine and Isolation

Last update on January 12, 2026

What is the difference between quarantine and isolation?

Quarantine and isolation both prevent or slow the spread of contagious disease.

Quarantine separates people who have been exposed to a contagious disease, like measles or COVID-19, to see if they become sick.

Isolation separates people who already have symptoms, suspect they have symptoms, or have a confirmed case of the contagious disease.

Should I quarantine if I have been exposed to a contagious disease?

Exposure to disease can happen in public spaces, like schools, offices, stores, waiting rooms of medical buildings, or in your home from people you live with. If you suspect you have been exposed to a contagious disease, contact a healthcare professional. If you’re vaccinated against the disease, you may need to monitor for symptoms. If you’re not vaccinated against the disease, a healthcare professional may recommend vaccination and/or quarantine, depending on your medical history and the severity of the disease.

I hear many people must quarantine because of the recent spread of measles. Is quarantine required?

Most instances of quarantine and isolation are not required. However, in response to severe health threats, states can require quarantine and isolation to protect the health and safety of their communities.

People who arrive in the United States from other countries may be subject to a required quarantine or isolation if they show symptoms or come from areas with outbreaks of the following diseases:

Cholera
Diphtheria
Infectious tuberculosis
Plague
Smallpox
Yellow fever
Viral hemorrhagic fevers
Severe acute respiratory syndromes
Flu that can cause a pandemic
Measles

What is the process of quarantine and isolation? Why is it important?

People who are asked to quarantine or isolate should stay at home and away from other people in their households, and monitor for new or worsening symptoms. People should contact a healthcare professional if their symptoms are severe or life-threatening, like trouble breathing or an inability to eat or drink. Healthcare professionals can also suggest alternative preventative measures if fully isolating from others in one’s home isn’t possible.

In addition to self-monitoring for worsening symptoms, some people who are asked to quarantine may be contacted by public health departments to determine if they have developed symptoms.

Quarantine and isolation can last for a few days or several weeks, depending on the contagious disease and the severity of symptoms.

I remember quarantining during COVID-19. Did it work?

Quarantine and isolation were important public health recommendations during the COVID-19 pandemic. They helped slow the spread of disease and helped reduce the burden on hospitals and medical professionals when cases were surging across the country.

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