Yes, someone who is actively sick with COVID-19 can spread the illness to others. The CDC recommends that these patients be isolated either in the hospital or at home (depending on how sick they are) until they are better and no longer pose a risk of infecting others.

How long someone is actively sick can vary so the decision on when to release someone from isolation is made on a case by case basis in consultation with healthcare providers, infection prevention and control experts, and public health officials and involves considering specifics of each situation including disease severity, illness signs and symptoms, and results of laboratory testing for that patient.

Current CDC guidance for when it is OK to release someone from isolation is made on a case by case basis and includes meeting all of the following requirements:
• The patient is free from fever without the use of fever-reducing medications.
• The patient is no longer showing symptoms, including cough.
• The patient has tested negative on at least two consecutive respiratory specimens collected at least 24 hours apart.