When you are flying from Nepal to the US, the US Center for Disease Control requires you to perform a Covid test within 24 hours of your flight. Most labs in Nepal offer the PCR test and that has become the de facto standard.

PCR test is not needed on the outbound to Nepal. Just full vaccination & completion of online CCMC form. On the return, you do need to take the PCR within 24 hours of your flight. You can follow the guidelines at zentravels.com which is current. https://zentravels.com/covid-19-advisory/

For additional information, you can call Zen Travels 202-552-1508 from the US or 01-597-0995 when in Nepal.

Bon Voyage.