Under current CDC guidance, you stay home until your symptoms have been improving for at least 24 hours and you’ve had no fever without using fever-reducing medication for that same 24-hour window. There is no longer a fixed five- or ten-day countdown for the general public. Once you meet both of those benchmarks, you can return to normal activities but should take extra precautions for the next five days.
How the Current Guidelines Work
The CDC updated its respiratory virus guidance in March 2024, moving away from a strict day count and toward a symptom-based approach. The two conditions for leaving isolation are simple: your overall symptoms are getting better, and you’ve gone a full 24 hours with no fever (and you haven’t taken anything like ibuprofen or acetaminophen to suppress one). If both are true, you can go back to work, school, or other activities.
If your fever returns or your symptoms get worse after you’ve resumed normal life, the clock resets. You go back to staying home and away from others until you again hit 24 fever-free hours with overall improvement.
The Five-Day Precaution Window
Ending isolation doesn’t mean you’re no longer contagious. Research on the Omicron variant found that vaccinated people with mild or no symptoms can shed live, infectious virus for six to nine days after their symptoms started or their first positive test, even after they feel better. That’s why the CDC recommends five additional days of precautions once you’re back out in the world.
During those five days, you’re encouraged to wear a well-fitting mask when you’re around other people indoors, keep physical distance when possible, improve ventilation (open windows, use air purifiers), and practice careful hand hygiene. You can also use rapid antigen tests during this window. A negative result is a reasonable signal that you’re less likely to spread the virus, though no single test is a guarantee.
If you never developed symptoms but tested positive, the same five-day precaution period applies starting from the date your positive test specimen was collected.
Counting the Days Correctly
If you’re tracking days, the terminology matters. Day zero is the day your symptoms first appeared (or the day your positive test specimen was collected, if you never had symptoms). Day one is the next full day after that. So when older guidance referred to “five days of isolation,” that actually meant days one through five, with day zero not counted.
If you test positive without symptoms and then develop symptoms within ten days, your timeline restarts. The day your symptoms began becomes the new day zero.
When Illness Is Severe
People who were hospitalized, needed intensive care, or required ventilation support may remain infectious longer than someone with a mild case. CDC guidance for severe illness calls for at least ten days of isolation from symptom onset, potentially extending up to 20 days. The same fever-free and symptom-improvement criteria still apply before isolation ends.
Immunocompromised Individuals
If you’re moderately or severely immunocompromised, your body may take much longer to clear the virus. The recommended isolation period is at least 20 days, and ending it typically involves serial testing: two consecutive negative rapid antigen or molecular tests collected at least 24 hours apart, along with the standard fever-free and symptom-improvement requirements. This process is best managed with input from an infectious disease specialist, because some immunocompromised people remain infectious well beyond 20 days.
Healthcare Workers Follow Stricter Rules
If you work in a healthcare setting, your employer likely follows a more cautious protocol. Healthcare workers with mild to moderate illness are generally expected to stay out for at least seven days if they can produce a negative test within 48 hours of returning, or ten days if they don’t test or still test positive around days five through seven. Those with severe illness follow the same 10-to-20-day window as the general severe-illness guidance. Immunocompromised healthcare workers use a test-based strategy requiring two consecutive negative results collected 48 hours apart.
How the WHO Differs
The World Health Organization recommends a longer timeline: ten days from symptom onset, plus three additional days after symptoms have stopped. That’s notably more conservative than the current CDC approach. If you’re traveling internationally or following guidance from a country that aligns with WHO recommendations, you may need to isolate longer than what U.S. guidelines suggest.
Using Rapid Tests to Guide Your Decisions
A rapid antigen test won’t tell you the exact moment you stop being contagious, but it’s a useful tool. A study from a large university’s managed isolation program found that 53 to 74 percent of students tested negative by isolation day five, while 15 to 22 percent were still positive on day six. If you’re trying to protect a vulnerable household member or heading to a gathering, testing before close contact gives you an additional layer of information. Two negative rapid tests taken a day or two apart provide stronger confidence than a single result.