Japan Pension Service began full operations Monday, succeeding the Social Insurance Agency after that body was shut down at the end of last month for mishandling pension records on a massive scale.
Health, Labor and Welfare Minister Akira Nagatsuma told employees to be aware of the new entity's uphill battle to regain public trust after the records scandal.
Many of the workers are from the old SIA, although they have lost their status as government employees.
"No failures will be allowed at the new organization. Have a spirit that you are supporting people's retirement life," Nagatsuma told an opening ceremony at the headquarters in Suginami Ward, Tokyo.
The new entity was put in place Friday and began full operations Monday after the holidays.
Nationwide, 312 pension service offices tasked with collecting premiums and other duties also started Monday.
The pension scandal became a major political issue and is seen as one of the causes behind the Liberal Democratic Party's loss in the general election last August.