When opening up the search interface in Maps, COVID-19 testing is now the first option in the list, and tapping it brings up all of the testing sites in your local area.
Tapping on one of the testing site entries provides a link to the hospital or testing site’s website with specific information on how testing is done, such as whether a doctor’s referral or an appointment are required to have the testing conducted.
Apple on April 11 launched an online portal allowing healthcare providers, labs, hospitals, and other businesses to register as COVID-19 testing locations. The Apple Maps team reviews each application before allowing approved sites to be displayed on Apple Maps. As pointed out by Engadget, the testing site list is available in all U.S. states and Puerto Rico.
Apple in early April updated the Maps app to prioritize searches for groceries, food delivery, pharmacies, hospitals, and urgent care, and these categories also show up with COVID-19 testing sites.