Social security organization in Iran covers more than half of the country’s population and is the biggest pension fund in Iran. Future life and fate of many depends on this organization’s destiny. Unsuitable situation of the fund due to low dependency ration and increasing deficit has forced the organization to cash in government debt as mean to protect its beneficiaries. This article, at first, investigates legal roots resulting into this amount of unpaid debt by government. Then, as the second step, an autoregressive distributed lags model is employed to study short and long term impact of various factors and different last regulations. It was shown that government debt from 850 thousands billion rials in 1993 will be increased to 4500 thousands billion in 1400, based on status quo scenario. This huge amount of debt beside bad financial situation of government indicates the necessity of reimbursement of debt in order to protect insurers and pensioners.