In the era of the Internet of Communication Technologies (ICT), the Internet is becoming more popular and widely used across the world. Radio Frequency IDentification (RFID) has become a prominent technology in healthcare systems for identifying tagged objects. The RFID tags are attached to the billions of different healthcare devices or things in several associated applications. However, RFID tags’ security and privacy are regarded as the two biggest concerns. An adversary might eavesdrop, tamper, or even intercept the transmitted messages in RFID systems. Also, the privacy of the users (patients, doctors, and nurses) may breach. In past years, numerous ultralightweight RFID authentication schemes have been proposed in the healthcare sector. However, all these schemes were pointed out as insecure under several known security attacks namely, replay, impersonation, full-disclosure, and de-synchronization attacks. Keeping in view such security flaws, we present an efficient and reliable ultralightweight RFID authentication scheme (ER²AS) for healthcare systems to enhance patients’ medication safety. The scheme employs bitwise XOR, circular left–right rotations, and our proposed ultralighweight reformation operation to achieve higher-level security. The security and privacy evaluations demonstrate that ER²AS scheme resists several known security attacks. The performance analysis also demonstrates that it incurs lower computation and storage overhead on the RFID tags, thus making it practical to be implemented in real-time healthcare environments.