The COVID-19 pandemic has significantly affected data collection for the nation's primary source of household-level labor force data, the Current Population Survey (CPS). In the first four months of the pandemic (March-June 2020) the average month-over-month nonresponse rate increased by 62 percent, while the size of newly entering cohorts declined by 37 percent relative to the prior 18 months. Together, these factors reduced the overall sample size of the CPS by around 17 percent. Both of these changes appear related to the cessation of in-person interviewing, a change which appears to be associated with significant shifts in the demographic composition of the sample. We find some evidence that these changes may affect the accuracy of subgroup unemployment estimates. Our primary aim is to advise researchers that the representativeness of the workhorse survey of labor economics, which has been and will be instrumental in identifying the labor market effects of COVID-19, was itself affected by the pandemic.