Fiber Reinforced Polymers(FRP)are becoming a popular strengthening alternative for deficient concrete structures.Since their introduction in civil engineering applications a few decades ago,a wealth of knowledge has been produced allowing the development of design guidelines and codes.One of the last steps in developing design provisions is the calibration of design factors to ensure that structures designed using these provisions achieve the intended reliability levels of Load and Resistance Factor Design(LRFD)codes.In this paper,we summarize efforts by the author to assist code committees to calibrate design provisions for four different structural elements,namely reinforced concrete under flexure,prestressed concrete under flexure,reinforced concrete beams under shear,and segmental prestressed concrete under shear for service load conditions.The first Order Reliability Method(FORM)is utilized to perform calibration of design provision to achieve a target reliability index that reflects current practice and the attributes of FRP strengthening such as lower ductility compared to conventional strengthening methods.Where there is no clear consensus on a target reliability index,the calibration is performed for different values to assist code writing committees in their work.Lessons learned from this experience is presented and recommendation for future efforts are made.