Before the 2009 re-election, Bloomberg vowed to change perhaps as many as 15 commissioners, many of whom were on their eighth year of service. Agencies that have had commissioner changes in Bloomberg's third term so far include Housing, DoITT, Corrections, Environmental Protection, and two at Education.

Mattingly will step down in September. A replacement has not yet been announced.

UPDATE: Public Advocate Bill de Blasio praised Mattingly, saying he "never hesitated to work collaboratively and make changes when they were most needed."