最近关于回美国的新冠测试要求做了点research, 也参考了版上的有用帖子。具体信息和官方要求会有更新，大家最好事先查清楚。下面只是我近来找的信息。 入境美国，CDC要求入境要出示一天内（calendar day, not 24 hours）的新冠阴性测试结果，包括打过疫苗的人。旅行回来的人可以选择在出发地机场或诊所等地方做测试的证明，但最方便的是离开美国前预定网上的virtual home tests services, 在出发前收到测试盒，带着出境旅行，然后约好时间，在医护人员视频监测下做测试，一般半小时或一两小时内可以email收到结果，入境时出示图像就可以了。 目前CDC认可的入境美国居家测试有三种： Abbott’s BinaxNow COVID-19 Home Test, Ellume’s COVID-19 Home Test and Qured’s video-supervised rapid antigen test.
下面是我查到的几家virtual home tests services： iHealth $25 virtual service + $20/2 kits https://ihealthlabs.com/products/ihealth-verified-covid-test-service 价格优惠，测试盒CVS也有，价格和他们网站价格差不多。 但目前网上只能订测试盒（2 tests pack), virtual service sold out. 而且必须用笔记本视频，不接受手机。 2.eMed $150/6 kits https://www.emed.com/products/covid-at-home-testkit-six-pack 接受手机和笔记本视频。但目前必须买6盒的大包装。 3.Optum https://store.optum.com/shop/products/abbott-binaxNOW-COVID-19-ag-emed-at-home-test-kit-2-pack/ $70/2 kits 2盒一套的套餐还有，也包括视频服务。但一盒单独的套餐$50/1 kit目前没货： https://store.optum.com/shop/products/abbott-binaxNOW-COVID-19-ag-emed-at-home-test-kit-1-pack/ 4.Ellume $50+运费$15 https://www.azova.com/testing/ellume/ 也有只含视频服务不含测试盒的（$20）。测试盒在 CVS有，大约$40/1 kit。 5.Qured https://thepointsguy.com/news/ba-qured-testing-for-travel/ 一家似乎是英国的公司，但测试结果明确说明是英美两国入境都适用的。测试盒是美国分部发货。我最后选的它家一个测试盒加视频的套餐，$35。也有两个测试盒或更大包装的套餐。order以后马上有Email， 用里面的code可以立即去他们网站登记和约测试时间。过程操作很容易。 另外更多信息： 参考网页之一 https://thepointsguy.com/news/at-home-covid-testing-travel/ What Should Be Included In Your Covid Test For US Travel? Most testing locations give the option of giving you your test results in either paper format or an as an electronic copy. We recommend that you get a copy of both since different airlines and ports of entry require different variations. The test result should include Type of test (indicating NAAT or antigen test) Passport number of the traveler Name and identifying details of the traveler including date of birth Who issued the result – namely, laboratory, healthcare entity, or telehealth service and their contact information including their phone number, fax number, & email address Date of the test – Since the US requires that the negative test result show a COVID-19 test taken within 1 day before departure, the date should be mentioned clearly. If using a recent positive test result with documentation of recovery from COVID-19 instead of a negative COVID test, the positive test should be taken within 90 days before travel. Final test result, which should be negative before travel. Which Covid Tests Are Acceptable For US Travel? US requires that you get tested 24-hours prior to boarding a flight headed to the US. The most commonly accepted Covid tests is the RT-PCR test. However, some locations also offer the nucleic acid amplification test (NAAT), which is also acceptable for US travel. Important to note is that Antibody tests are not accepted to board a flight to the USA. The following other tests are acceptable for US travel: LAMP test TMA test NEAR test HDA test
入境美国，CDC要求入境要出示一天内（calendar day, not 24 hours）的新冠阴性测试结果，包括打过疫苗的人。旅行回来的人可以选择在出发地机场或诊所等地方做测试的证明，但最方便的是离开美国前预定网上的virtual home tests services, 在出发前收到测试盒，带着出境旅行，然后约好时间，在医护人员视频监测下做测试，一般半小时或一两小时内可以email收到结果，入境时出示图像就可以了。
目前CDC认可的入境美国居家测试有三种：
Abbott’s BinaxNow COVID-19 Home Test, Ellume’s COVID-19 Home Test and Qured’s video-supervised rapid antigen test.
下面是我查到的几家virtual home tests services：
iHealth $25 virtual service + $20/2 kits https://ihealthlabs.com/products/ihealth-verified-covid-test-service 价格优惠，测试盒CVS也有，价格和他们网站价格差不多。 但目前网上只能订测试盒（2 tests pack), virtual service sold out. 而且必须用笔记本视频，不接受手机。
2.eMed $150/6 kits https://www.emed.com/products/covid-at-home-testkit-six-pack 接受手机和笔记本视频。但目前必须买6盒的大包装。
3.Optum https://store.optum.com/shop/products/abbott-binaxNOW-COVID-19-ag-emed-at-home-test-kit-2-pack/ $70/2 kits 2盒一套的套餐还有，也包括视频服务。但一盒单独的套餐$50/1 kit目前没货： https://store.optum.com/shop/products/abbott-binaxNOW-COVID-19-ag-emed-at-home-test-kit-1-pack/
4.Ellume $50+运费$15 https://www.azova.com/testing/ellume/ 也有只含视频服务不含测试盒的（$20）。测试盒在 CVS有，大约$40/1 kit。
5.Qured https://thepointsguy.com/news/ba-qured-testing-for-travel/ 一家似乎是英国的公司，但测试结果明确说明是英美两国入境都适用的。测试盒是美国分部发货。我最后选的它家一个测试盒加视频的套餐，$35。也有两个测试盒或更大包装的套餐。order以后马上有Email， 用里面的code可以立即去他们网站登记和约测试时间。过程操作很容易。
另外更多信息： 参考网页之一 https://thepointsguy.com/news/at-home-covid-testing-travel/
What Should Be Included In Your Covid Test For US Travel?
Most testing locations give the option of giving you your test results in either paper format or an as an electronic copy. We recommend that you get a copy of both since different airlines and ports of entry require different variations.
The test result should include
Type of test (indicating NAAT or antigen test) Passport number of the traveler Name and identifying details of the traveler including date of birth Who issued the result – namely, laboratory, healthcare entity, or telehealth service and their contact information including their phone number, fax number, & email address Date of the test – Since the US requires that the negative test result show a COVID-19 test taken within 1 day before departure, the date should be mentioned clearly. If using a recent positive test result with documentation of recovery from COVID-19 instead of a negative COVID test, the positive test should be taken within 90 days before travel. Final test result, which should be negative before travel.
Which Covid Tests Are Acceptable For US Travel?
US requires that you get tested 24-hours prior to boarding a flight headed to the US. The most commonly accepted Covid tests is the RT-PCR test. However, some locations also offer the nucleic acid amplification test (NAAT), which is also acceptable for US travel. Important to note is that Antibody tests are not accepted to board a flight to the USA.
The following other tests are acceptable for US travel: LAMP test TMA test NEAR test HDA test
Calendar day 意思就是可以接受超过24小时的测试，比如你周日下午的回程航班，那周六上午做的测试也可以用。这个规定其实是比较人性化的，是考虑到有转机的情况，加上中间等的时间，会超过24小时。
我的理解，和航空公司没关系。
有最近用emed回美的朋友上来报告一下更好。