The Diet enacted a law Friday intended to grant extra pension payments for pensioners whose benefits fell short due to the record-keeping fiasco.
The opposition-controlled House of Councilors unanimously passed the bill, which had already cleared the House of Representatives.
The average sum of back money to be added to regular pension benefits will be about ¥16,000, government officials said.
The additional payment will go to pensioners who have not received their benefits for more than five years. Pensioners who have not received their benefits for less than five years, however, will receive no such money, government officials said.
The scheme is expected to cover around 2.6 million pensioners in the initial year.
The government expects about ¥56 billion will be necessary as revenues for the scheme in the initial year.
The officials said an average case might involve a pensioner who did not receive ¥58,000 a year for 15 years between the ages of 60 and 75. In such a case, about ¥16,000 a year will be paid as an extra payment for the 10 years until the pensioner turns 70.
The pension record fiasco, which involves more than 50 million unidentified pension accounts, developed into a major political issue and was one of the reasons the Liberal Democratic Party-New Komeito ruling bloc lost its Upper House majority in the 2007 election.