The objective of this paper is to present the design of flexible meandered loop antennas which is loaded with CSRR and SRR for implantable application. The design of flexible meander loop antenna is done and then modification is done to propose two antennas. One proposed antenna is loaded with CSRR and other is loaded with SRR. The proposed antennas operates in multiband frequencies like the 402–405 MHz Medical Implant Communication System (MICS) band and the Industrial, Scientific and Medical (ISM) bands which ranges from 433.1–434.8 MHz, 868–868.6 MHz, 902.8–928 MHz, and 2400–2500 MHz which is assigned for medical implantable device application. The introduction of CSRR and SRR in the flexible meandered loop antenna improves the return loss at the desired multiband frequencies. The parametric study is done to obtain the desired return loss at the expected frequency bands. A reduction in the Specific Absorption Rate of the proposed antennas is also observed. The size of the antennas becomes compact as a result of its flexible nature. The dimension of the antennas is 4.5 mm radius and 16mm height which is an acceptable dimension for implantable devices. A comparative study is done and presented in this paper to show the impact of single and dual ring CSRR on the performance of the flexible meandered loop antenna. The parametric study is done to optimize the position of the SRR to get good return loss at desired bands and the comparison of the results is presented in this paper. The designing and simulation of the proposed antennas is done using 3D EM simulation software CST Microwave studio v.15.0.