Magnetic resonance-based wireless power delivery provides a harmless way for powering implantable biomedical devices. This technique uses two coils operating at the same frequency and transfers power via resonance-based inductive coupling. Considering the operating cost and safety, high power transmission efficiency is crucial. In this case, the substantial quality factor and matched resonant frequency are required to achieve high efficiency. However, the space available for the receiver coil is strictly constrained for the implantable device and the minimum separation between two coils will be at least 2 cm. Thereby, the transmission efficiency is bounded. This paper is based on the design constraints to demonstrate the step-by-step design procedures of optimized efficient wireless power delivery systems in bio-implantable applications, considering the size limitations. © 2019 IEEE.