Abstract This paper analyses the time series properties of the unemployment rates of the US economy using a regional disaggregated level. Our results are, in general, favorable to the rejection of the presence of a unit root in these variables. However, we can also observe that this conclusion is clearly qualified by the level of disaggregation employed. We also find robust evidence in favor of the presence of some breaks in the evolution of these unemployment rates. We subsequently offer an estimation of the NAIRU, which is based on the use of the Bai–Perron procedure.