It’s welcome news that free COVID-19 test kits will soon be available again, given the virus’ ongoing ability to cause serious illness. Starting in late September, households can order up to four free tests through COVIDTests.gov, federal officials announced.

Many older kits obtained via the previous mail-order campaign have since expired, even with effective-date extensions, and retail costs average anywhere from $10 to $25 per kit. Consider the free test kits an important tool to stay healthy: enabling early detection to start medication early, and to isolate from others, especially when indoors.