The article discloses the peculiarities of forming the forming the contribution of the region's insurance sector in the gross regional product (GRP). The algorithm and the stages of transformation of cash flows in the system of insurance services reproduction and forming the GRP have been considered. It has been found that added cost which is formed at the stage of producing the insurance product is quantitatively formed in the process of value distribution. Certain suggestions have been formulated to improve the methodology of assessment of the contribution of the «Financial Corporations» sector and the «Insurance Corporations and Pension Funds» subsection