Significant research has been performed in recent years to develop load and resistance factor design (LRFD) methods for geotechnical applications. However, one lacking aspect of this work is application to design of earth slopes, including consideration of the overall stability of earth retaining structures. A procedure for implementing LFRD for slope stability evaluations is proposed in this paper, using "probabilistically calibrated" resistance factors established to achieve a range of target probabilities of failure. Results of probabilistic calibrations demonstrate that LRFD methods can be used for overall stability evaluations without unnecessary complications.