This paper proposes an miniaturized round antenna designed for implantable medical devices communication, such as pacemakers. The frequencies chosen are in the Medical Implantable Communication System (MICS) and ultra-high frequency (UHF) RFID and Industrial, Scientific and Medical (ISM) bands. The proposed antenna measures 15 mm in radius and 2.61 mm in thickness, which represents π × (0.2λ) × (0.2λ) × (0.0035λ) at 403 MHz. A C-shaped PCB between ground plane and resonator connected with short pins was employed for antenna adaptation. After the simulations on the CST MICROWAVE STUDIO software, good adaptations were obtained at 403 MHz, 915 MHz and also 2.45 GHz.