The evolution of fiscal revenues from the exploitation of natural resources has shown high volatility, reflecting both price variations and changes to the tax regimes. The fiscal reforms implemented during the last boom emphasized the specialization of tax systems in countries in the Andean region. In this context, this chapter analyzes the fiscal institutional framework in the extractive sector and its dynamic, focusing on fiscal reforms and their impact on public accounts, fiscal revenues and regional inequality, based on the study of some of the countries of the region (Argentina, Bolivia, Chile, Colombia, Ecuador, and Peru) for the period 1990–2016. This chapter also analyses the evolution of fiscal revenues and some indicators of regional inequality resulting from the combination of commodity specialization, legal framework and price cycle, focusing also in the main challenges in the post-boom context. Falling commodity prices since 2009 not only reduced related revenues but also spurred reconsideration of objectives and tools to promote sustainable production and investment of the commodity production sector and also compensation for lower tax revenues and their territorial impact. This issue is of special interest in the countries of the Andean region by several reasons: the high specialization in the extraction of natural resources observed in this region; the weakness of their public sectors to promote sustainable growth; the structural difficulties of these countries to achieve adequate and sustainable tax systems; and the high disparity in regional and personal income.