I would like to report an erratum to the paper titled ‘Learning curve estimation in medical devices and procedures: hierarchical modeling’ by Govindarajulu US et al., Statistics in Medicine. There was a mistake in two equations and we neglected to list our funding source. The correct expression is (Formula presented.) (Formula presented.) Note: Computations in our paper are correct and not affected by the correction to these expressions: FUNDING SOURCE Drs. Resnic, Matheny and Govindarajulu's efforts were funded, in part, by grant 1 U01 FD004493–01 (MDEpiNet Medical Counter Measures Study) from the U.S. Food and Drug Administration through a sub award from Harvard Medical School.