On December 13, 2016, the US Congress enacted the 21st Century Cures Act (hereafter the Cures Act), which contained the Final Rule mandate that took effect on April 5, 2021. Since then, health systems have been required to provide patients digital access to their eHealth information "without delay" and without charge. This study aimed to assess clinicians' initial experiences with, and attitudes toward, sharing visit notes with patients after being mandated to do so by the Cures Act and to determine clinician preferences regarding instant record release. This cross-sectional survey study was conducted between June 10, 2021, and August 15, 2021, at the University of Kansas Health System, a large academic medical center in Kansas City, Kansas, United States. Participants included clinicians currently employed by the health system, including resident and attending physicians, physician assistants, nurse practitioners, and critical care and emergency medicine registered nurses. A total of 1574 attending physicians, physician assistants, and nurse practitioners, as well as 506 critical care and emergency medicine nurses, were sent invitations; 538 (34.18%) and 72 (14.2%), respectively, responded. Of 609 resident physicians, 4 (response rate not applicable because it was unknown how many residents viewed the website while the link was available) responded. The majority of respondents were attending physicians (402/614, 65.5%) and within the department of internal medicine (160/614, 26.1%). Most agreed that sharing visit notes was a good idea (355/613, 57.9%) and that it is important to speak with the patients before they accessed their records (431/613, 70.3%). Those who agreed that sharing visit notes is a good idea tended to view the practice as a useful tool for engaging patients ("Agree": 139/355, 39.2%; "Somewhat agree": 161/355, 45.4%; P<.001) and experience no change in the clinical value of their notes for other clinicians (326/355, 91.8%; P<.001). Those who disagreed (or were neutral) tended not to encourage patients to read their notes (235/258, 91.1%; P<.001) and were more likely to experience a change in their charting practice (168/257, 65.4%; P<.001) and increased time charting (99/258, 38.4%; P<.001). The findings of this study may be generalizable to institutions similar to the University of Kansas Health System, and the clinician testimonies gathered in this study may provide valuable insight into the initial opinions and experiences of clinicians at these institutions. In addition, these clinician experiences collected early in the transition period may be used to guide future health policy implementation and to understand how best to prepare clinicians for these changes in practice.