Abstract: The Undiagnosed Disease Network (UDN) works with participants who have undergone a long diagnostic odyssey that has thus far not explained their medical condition. As a clinical site in the network, we accept and evaluate participants while developing strategies to end diagnostic odyssey’s. This requested supplement is an application for funds for activities not originally planned. We are requesting additional time, through 6/30/23, to complete these aims. These new aims are: Aim 1: Bear increased costs to accept participants from out of our original Pacific Northwest area from 7/1/22 to 6/30/22. Aim 2: Enroll and evaluate new participants 3/1/23- 6/30/22 after the original planned and funded enrollment ends in February 2023, focusing on recruitment of under-insured and otherwise medically underserved individuals. The overall goal is to make the UDN accessible to more participants.