If the UW filed a timely application for an extension of your H-1B, E-3, O-1, or TN status, you can remain in the U.S.
and continue employment for the same employer (the UW)
for, generally, up to 240 days beyond the expiration of your current H-1B, E-3, O-1 or TN while your extension petition is pending with USCIS.
To verify you qualify for the 240-day grace period, IFSS will place a sticker on your I-797C receipt notice indicating your new work authorization expiration date under the 240-day grace. You may show the original receipt notice as part of your I-9 verification documentation. Additionally, the Wisconsin DMV will recognize the 240-day extension if you need to renew your Wisconsin driver's license and cannot wait for the approval to arrive.
Legal citation:
8 CFR Part 274a.12(b)(20)