Corrosion damage is one of the main problems which is affecting the durability of concrete bridge piers in marine environment. This paper presents condition-rating method followed by load rating calculations are used for evaluating existing bridge pier in the coastal region. For estimating the condition of piers in marine environment, Duracrete model is used for initiation time of corrosion and time variant corrosion rate model is used in propagation phase. During the propagation phase, several factors like loss of rebar cross-section, cover cracking, and reduced yield strength of rebar with time. The time-dependent characteristics of the axial load-bending moment interaction diagrams are developed for corrosion damaged bridge piers using equilibrium and strain compatibility concepts at different stages of service life. From the results, it is observed that the rating factor is reduced with time due to deterioration of bridge pier. However, the axial load carrying capacity is safe in all parameters at the end of service life in marine environment.