federal government is once again offering free home test kits to Americans and for more on this we are joined by CBS News medical contributor Dr Celine gounder who is also editor at large for public health at kff Dr Gander thank you very much for being here so free kova test once again why now so as of yesterday covetest.gov is up and running again the government wants to make sure everybody every household has tests on hand ahead of the holidays because you have people of different Generations who are coming together close together over the holidays so it's a risk for Grandma Grandpa we just want to make sure that people know if they have covet and might be infectious to others a lot of us have those tests stockpiled and some of them have expired does that still work sometimes with food sometimes it's medication even though it's expired you can still eat it or it's perspective so the FDA has extended expiration dates on the test there's actually information about this on the cbsmornings.com website you can look up your specific brand and see if yours is still valid