From the Centers for Disease Control:
https://www.cdc.gov/coronavirus/2019-ncov/php/open-america/contact-tracing-resources.html

Contact tracing steps

Generally, contact tracing includes the following steps:

• Case investigation: Public health staff work with a patient to help them recall everyone they have had close contact with during the time they may have been infectious.
• Contact tracing: Public health staff begin contact tracing by notifying exposed people (contacts) of their potential exposure as rapidly and sensitively as possible, not revealing the infected patient’s identity.
• Contact support: Contacts are provided with education, information, and support to help them understand their risk, what they should do to separate themselves from others who are not exposed, and how to monitor themselves for illness. In addition, they are informed of the possibility that they could spread the infection to others even if they do not feel ill.
• Self-quarantine: Contacts are encouraged to stay home, monitor their health, and maintain social distance (at least 6 feet) from others until 14 days after their last exposure to the infected patient, in case they also become ill.

LEARN MORE HERE https://www.cdc.gov/coronavirus/2019-ncov/daily-life-coping/contact-tracing.html