AbstractFor the purposes of economic incentives or social equity, the Moroccan tax system has always had exemptions aimed at reducing the tax burden of certain categories of taxpayers or sectors of activity. These derogations represent a considerable loss of revenue for the state budget, as are budgetary expenditures. It is for this reason that they are called "tax expenditures" because they represent, in fact, a tax product that the State has waived to collect without however ensuring the achievement of the objectives assigned to it. Unlike budget expenditures, these tax expenditures are not subject to quotas. They are not subject to the same control and monitoring rules as budget expenditures.However, according to the latest report annexed to the budget bill of the 2018 budget year the overall amount of the shortfall for the treasury is 34 MDH. This staggering amounts to a few differences, to the overall amount of the budget deficit recorded the same year.To stick to a purely accounting reading, to mop up the public deficit, it is enough to make a clean sweep of all the derogatory provisions undermining the Moroccan tax system and make this rejection in one block with two birds: on the one hand, to stop the costly drift contributing to the widening of the budget deficit; on the other hand, to put an end to the nebulous world of tax expenditures, which calls into question simple and effective simple taxation.But to advocate such an alternative proves to be simplistic and reduces the extent of the issue of tax expenditures. To project, thus, to get rid of all the derogatory arsenal without discernment, it is to question the role conferred with the tax since always, that of instrument of public policy ultimate.Moreover, according to the rules of good governance, any government intervention in the management of public affairs should be effective. To do this, the government, when implementing its economic and social development program, should use the most appropriate and most conducive instrument in terms of performance, but especially at the lowest cost to the community. Thus, and whenever the public authorities resort to the tax expenditure and not to the traditional budgetary expenditure, one would understand that this choice was dictated to them by the feasibility study which would have been carried out before the decision making. The conditional used is by no means insignificant because in the current state of things, the approach thus set out is only wishful thinking. The rationality of tax expenditures is nevertheless one of the flagship recommendations of the National Tax Conference held in 2013. It is therefore a question of assessing the degree of implementation of this recommendation which forced us to review the five finance laws that have succeeded the National Tax Conference in question.But before approaching this stage of analysis, it seemed to us indispensable, given the confusion and the conceptual and juridical vagueness surrounding the notion of tax expenditures, to contribute to giving a definition, now missing in Moroccan tax literature. To do this, we first tried to return to the original version of the concept of tax expenditures as it was coined by its designer Stanley Surrey. This retrospective analysis allowed us to note the conceptual slippage and misuse of language that this notion has experienced. Subsequently, we considered it useful to review the Moroccan management of tax expenditures as well as its imperfections and defects.In conclusion and in order to make a contribution, a clear and concise definition and several recommendations have been proposed in order to rationalize the incentive system by imposing strict and mandatory control and monitoring rules so that the expenditure public is no longer synonymous with the waste of public money.Keywords : Budgetary expenditure, tax expenditures, exemptions, exemptions, budget law, corporation tax, income tax, value added tax