Prior to 2000, workers did not have the freedom of choosing which "Obra Social" they contributed to and were covered by. This situation gave rise to some problems; e. g. a teacher living in a city where the gastronomy workers' "Obra Social" provided better care than the teachers union's "Obra Social" could not freely switch plans even when it would have been in their best interest. This was mended in the year 2000 when National Decree 446/2000 was signed into law which established changes to the regulation of "Obras Sociales," allowing for workers to choose freely between "Obras Sociales" administered by different workers unions (although they are still obligated to adhere to one of the "Obras" and make regular payments).