The inspector general probe found no instances during 2009 and 2010 in which there was more demand for commemorative stamps than supply.
The best-selling commemorative issued by the Postal Service was a 29-cent stamp issued in 1993 on what would have been Presley's 58th birthday. A Marilyn Monroe stamp issued in 1995 for 32 cents was another top seller.
Stamps issued in March featuring the cherry blossom trees ringing Washington's Tidal Basin oversold initial expectations and were reprinted, Saunders said. Other stamps that sold more than their initial print runs were the 1997 Bugs Bunny series and a 2010 series featuring animal shelter pets, he said.
The Postal Service has cut stamp production in line with falling demand for first-class mail, which includes letters and bills. It printed 21 billion stamps in the 2011 fiscal year. costing $43 million, down from 29.7 billion stamps. costing $56 million. in fiscal 2009, the report said.
First-class mail volume continued to decline in the quarter ended June 30, falling 3.5 percent compared with a year earlier, as people and businesses shift to e-mail and electronic transactions.