The conservative Heritage Foundation’s $6.3 trillion cost estimate for the amnesty bill is overstated because taxpayers are already on the hook to pay most of the costs used to calculate that total, said Robert Lynch, an immigration expert at the progressive Center for American Progress.

Heritage’s comprehensive prediction that it will cost $6.3 trillion over 50 years to legalize 11 million undocumented immigrants includes the cost of putting all of them on national retirement programs, such as Social Security and Medicaid.

But current law allows American-born, adult children of illegal aliens to seek green cards for their parents and siblings, Lynch told a May 29 panel discussion hosted by the Bipartisan Policy Center.