Public budgets in Germany developed favorable during the last years. Currently there is a broad discussion on how to spend unexpected budget surpluses: tax reductions and a various number of spending purposes are on the agenda. Many of the proposals overlook that existing surpluses partly reflect special developments and are, thus, only temporary. This part of surpluses indicates no scope for tax reductions or lasting expenditure, but it can temporarily be used on investment spending and, thus, can enhance potential growth. In many cases proposals also overlook that the development of public finances in Germany is very heterogeneous. Regarding demographic developments social security systems will face heavy challenges and will have to raise social contribution rates in near future. A medium-term projection indicates an increase of nearly four percentage points till 2025. This dampens economic development and reduces potential growth. Thus, the permanent part of the budget surplus should be used to increase tax transfers to social insurances – especially because a huge volume of non-insurance benefits is still financed within the security system.