Cyber-Physical Systems (CPS) in healthcare is one such technology that has been instrumental in healthcare delivery. Compared with general CPS, medical CPS has requirements for real-time data processing directly related to the safety of patients and is associated with personal health information, a particular category of sensitive personal information that is subject to privacy law. Existing security mechanisms like two-factor authentication, biometric controls, CAPTCHA, etc., often present significant usability challenges for people with diverse physical and cognitive disabilities. This chapter addresses the usability consequences for different user groups and the accessibility of security measures. It then suggests adaptive or context-aware security solutions and suitable authentication approaches to enhance usability without compromising robust security. The chapter ends with research challenges and represents various approaches to designing the medical CPS and future directions, highlighting the importance of collaboration in designing a secure medical CPS that is well-adherent to patient safety, privacy, and trust.