WASHINGTON – The bipartisan Senate immigration plan would boost Social Security, its chief actuary said Wednesday, as more immigrants come out of the underground economy and begin paying taxes.

The assessment of the bill’s impact on Old-Age, Survivors and Disability Insurance is another entry in a growing body of economic data on both sides of the immigration reform debate.

“Overall, we anticipate that the net effect of this bill on the long-range OASDI actuarial balance will be positive,” Stephen C. Goss, the chief actuary of the Social Security Administration, wrote in a letter to Sen. Marco Rubio, R-Fla., an architect of the bipartisan legislation.

The chief actuary wrote that the number of workers paying taxes into the system would increase as the bill provides legal status for the estimated 11 million immigrants who entered the country illegally or overstayed their visas.

“Many of these individuals already work in the country in the underground economy, not paying taxes, and will begin paying taxes,” the letter said.