Reinforced concrete (RC) bridge columns with inadequate lap splices in the longitudinal reinforcement are very vulnerable. They are even more critical in corrosive environments. Corrosion of steel bars decreases the steel section, reduces ductility, and deteriorates the bond between the steel reinforcing bars and the surrounding concrete. The base of a bridge pier, where the main reinforcing bars are lap spliced with starter bars, is a bond-critical region in RC bridges. This paper presents a model for estimation of the stress at corroded lap-spliced bars for tension-controlled RC column sections. The amount of stress in the steel bars at the ultimate limit state was estimated based on the experimental data of bond stress between the steel bars and concrete. Using the bond strength of corroded and non-corroded steel bars, stress of corroded lap-spliced bar is expressed in terms of corrosion rate and the original yielding strength. The results of this investigation suggest that corrosion of lap-spliced steel bars has significant impact on the load transfer between the lap-spliced bars and, consequently, drastic decrease in the flexural capacity of bridge columns.