# Are ability estimates given by ltm and mirt Z-scores?

Are the ability estimates given by fscores in mirt and factor.scores in ltm Z-scores? That is, so long as the relevant ability can be assumed to be normally distributed in the population, is someone with an ability estimate of 0 estimated to be of mean ability, someone with an ability estimate of 1 estimated to be one standard deviation above mean ability, and so forth?