COVID-19 testing involves taking a swab from the patient's mouth or nose, sending it to a lab, and receiving a positive or negative result.

Judged as a summary of standard COVID-19 diagnostic testing as of March 2020. True: CDC/WHO or public-health guidance from that time describes the standard test as a nasopharyngeal, oropharyngeal or nasal swab sent to a laboratory (RT-PCR), returning a positive or negative result. Mostly true: this was the dominant process, but a minor detail differs, for example inconclusive results or other specimen types. Mixed or mostly false: the standard process at that time differed in a material way, for example the main tests did not use swabs or were not lab-based. False: the description does not match how COVID-19 tests were done in March 2020.

Set before the research began.

1. E1 03/15/2020: Lab Advisory: Updated Interim Guidelines for Collecting, Handling, and Testing Clinical Specimens from Persons Under Investigation (PUIs) for Coronavirus Disease 2019 (COVID-19) U.S. Centers for Disease Control and Prevention (CDC), Laboratory Outreach Communication System · 15 March 2020

   “with the CDC Emergency Use Authorization (EUA) COVID-19 real-time PCR assay, CDC recommends collecting only the upper respiratory nasopharyngeal (NP) swab.”

2. E2 [PDF] Overview of COVID-19 Testing Efforts Committee on Energy and Commerce (U.S. House of Representatives), circulated via Rep. Underwood's site · 19 March 2020

   “If you are a patient needing to be tested, a specimen will be collected, typically from the back of your throat or your nose, using a long swab.”

3. E3 What takes so long? A behind-the-scenes look at COVID-19 testing. Tampa Bay Times (Kaiser Health News reporting by Julie Appleby) · 30 March 2020

   “First, a sample is taken from a patient’s nose or throat, using a special swab. That swab goes into a tube and is sent to a lab.”

4. E4 Interim Guidelines for Collecting, Handling, and Testing Clinical Specimens from Persons for Coronavirus Disease 2019 (COVID-19): March 13, 2020 CDC Stacks (National Center for Immunization and Respiratory Diseases, Division of Viral Diseases) · 13 March 2020

   “Interim Guidelines for Collecting, Handling, and Testing Clinical Specimens from Persons for Coronavirus Disease 2019 (COVID-19): March 13, 2020”

CDC guidance from March 2020 describes the authorised real-time PCR test as using an upper-respiratory nasopharyngeal swab (E1). A House committee fact sheet and Kaiser Health News reporting from that month describe a swab from the nose or throat that is sent to a lab (E2, E3). This matches the claim's core description of the swab-to-lab process. Minor details differ: "mouth" is loose wording for a throat swab, CDC guidance issued two days after the statement recommended the nasopharyngeal swab only [E1], and the evidence does not explicitly describe the positive or negative result, so the verdict is mostly true.