Background: Under CDCs guidance for mitigating healthcare worker (HCW) staffing shortages, COVID-positive HCW may return to work as early as five days after their initial positive test without a negative antigen test, if symptoms are improving. Recent studies suggest a robust correlation between a positive COVID-19 antigen test and infectiousness. Methods: From January to June 2022, HCW employed by a large health system who tested positive for COVID on a PCR test were instructed to isolate and return for a rapid antigen test on day 5 or later if they had been fever-free for 24 hours and their symptoms were improving. We conducted chi-squared tests and a multivariate logistic regression to assess the association between demographic characteristics, vaccination status, and days from the initial positive PCR test on RTW antigen test results. Results: Compared to day 5, HCW had a lower odds of a positive antigen result on day 7 (OR: 0.39, p<0.0001) and after at least 8 days (OR: 0.16, p<0.0001). Unexpectedly, a positive antigen result was more likely among HCW who were vaccinated (OR: 1.41, p <0.05), boosted for more than 90 days prior (OR: 2.21, p<0.0001), and boosted within 90 days (OR: 2.08, p < 0.01) compared to not being vaccinated. Conclusions: Our findings suggest that HCW returning to work before day 7 following a positive PCR test may still be infectious and future guidelines addressing contingency staffing should reflect these findings in order to minimize possible transmission in the healthcare setting. The finding that boosted individuals had over twice the odds of returning positive on the follow up antigen test compared to unvaccinated HCWs merits additional research.