The paper presents a stochastic model and the algorithm for simulation of financial requirement of social benefits. The model of nonhomogeneous Poisson flows with delays formalizes the extrinsic information flows. A stochastic model for procedure of application for social benefit is given. We analyze theoretical basements of the model for the value of delay periods. We derive and statistically prove that this period fits to the family of the Gamma distributions. We formalize the necessary assumptions crucial for social benefits budget planning in a region of the Russian Federation.