PROJECT SUMMARY The COVID-19 pandemic has been devastating for nursing homes in the US. In response to the unprecedented threat posed by the pandemic, Medicare required SNFs to impose a number of measures to reduce the spread of COVID-19, including a ban on outside visitors. One consequence of this lockdown was an overnight transformation of the nature of care delivery in SNFs. Specifically, Medicare waived long-standing requirements around physician evaluation for SNF residents, including new flexibility for all SNFs to provide care remotely via telehealth, previously restricted to rural SNFs under specific conditions. Telemedicine has long been regarded as a promising innovation in care delivery for SNFs, whose residents have significant medical needs and impaired mobility. Unfortunately, adoption has been limited. The barriers to telemedicine use in SNFs are not clinical, but primarily misaligned financial incentives. Telemedicine requires investment in technology, training and culture change, but comes with little additional reimbursement. The COVID-19 pandemic dramatically changed the clinical motivation for SNFs to use telemedicine and the financial incentives for physicians to provide those services. Little is known about how SNFs have used telemedicine after COVID-19 emerged. There are many evidence gaps, such as understanding the extent of telemedicine adoption in SNFs, what services are delivered through virtual care, which sorts of physicians deliver them, and what factors contribute to variation in telemedicine use. Answers to these questions are necessary to advance policy for future reimbursement and use of this technology in SNFs moving forward. The objective of this K23 supplement is to characterize the adoption and use of telemedicine in SNFs for the care of COVID-19 and non-COVID clinical care. My overarching hypothesis is that the COVID-19 pandemic has vastly accelerated telemedicine adoption in SNFs for both COVID-19 treatment and other clinical care, especially at facilities with COVID-19 outbreaks. I propose two Aims: 1) Characterize the adoption and use of telemedicine for COVID-19 treatment in SNFs with COVID-19 cases and variation by patient, facility and geographic characteristics. 2) Characterize the delivery of all non-COVID-19 clinical care in SNFs with differing levels of telemedicine use before and during the COVID-19 pandemic. These Aims will provide detailed insight into how SNFs have adapted care delivery under unprecedented circumstances. Evidence on telemedicine adoption at SNFs can inform the future of Medicare regulation, state and federal investment in SNF telemedicine and the design of payment policy during future waves of COVID-19.