This paper describes the development of analytic first-order derivatives (gradient and derivative coupling vectors) for CASPT2 with IPEA shift (CASPT2-IPEA) as well as restricted active space (RAS) perturbation theory (RASPT2[-IPEA]) . The modification required to compute the energy with IPEA shift is relatively simple, but CASPT2-IPEA loses an invariant character of the original CASPT2 method, and two constraint conditions are also needed for formulating analytic derivatives. The origin of the problem is identified and solutions are discussed below in detail.