Pay My Bill. Navigating Medicare in Maryland. Contact: 410-821-4140 or 877-632-4909 (toll free),or CBOService@umm.edu. At the University of Maryland Upper Chesapeake Health, you can pay for your bill online using the below portal, or by cash, personal check or money order. For hospital patient accounts with a service/admit date of 3/15/2020 or ....