If you had COVID-19 with symptoms, the CDC considers you to be no longer contagious if you meet all three of these conditions:
Your fever has been gone for three days, without the use of fever-reducing medicine
Your respiratory symptoms (i.e. cough, shortness of breath) have improved
10 days have passed since you first experienced symptoms
You should check with your doctor or public health office before ending COVID-19 precautions like home isolation, especially if you’re in a high-risk group. If you tested positive for COVID-19 but were asymptomatic, you are considered no longer contagious if 10 days have passed since your positive test. You also are considered no longer contagious if you have two negative tests, with more than 24 hours in between. Also, exposed contacts, including members of your household, may become sick up to 14 days after their last day of contact with you when you were contagious.