Members of the Senate’s Gang of Eight have assured Americans their bill will not incur any costs.

“Our watchword here is to have this bill pay for itself,” Sen. Chuck Schumer, D-N.Y., one of the bill’s main advocates, told colleagues during the Senate Judiciary Committee’s markup.

But what about the taxpayer money already spent on persons no longer in this country?

Immigration and Customs Enforcement reports that for each illegal immigrant arrested, detained and deported, American taxpayers sustained a $12,500 tab. In just the 2012 fiscal year, that meant 324,299 people, according to the Department of Homeland Security’s Office of Immigration Studies.

American taxpayers will have spent roughly $11.3 billion in the last five years on the deportation of illegal immigrants only to have some of them allowed to return to this country.

In the proposed legislation, previously deported persons would be eligible to apply for “registered provisional immigrant” status as long as their deportation was not the result of a crime for which they were convicted and they are the spouse, child or parent of a U.S. citizen or green card holder. An estimated 900,000 deportees would meet the above criteria, according to an analysis performed by the Federation for American Immigration Reform, a nonprofit activist group that opposes liberalization of immigration law.

Mark Krikorian, executive director of the Center for Immigration Studies, a think tank dedicated to studying the fiscal consequences of immigration, believes that by allowing deportees to re-enter the country, legislators are effectively apologizing for enforcing the law.

“Essentially the bank robber gets out of jail and also gets to keep whatever money he stole,” Krikorian said. “It seems to be one of the most absurd elements of this legislation.”

Randy Capps, a senior policy analyst for the Migration Policy Institute, which believes the Gang of Eight bill adequately serves the national interest, sees allowing deportees to return as beneficial.

“I think that allowing deported parents to come back and work to support their families actually is going to save government money in the long run,” Capps said.

A recent report by the Heritage Foundation shows Capps might be onto something.

“During the interim phase immediately after amnesty, tax payments would increase more than government benefits,” the report indicates.

However, the Heritage Foundation does not see this lasting.

“Restricting access to benefits for the first 13 years after amnesty therefore has only marginal impact on the long-term costs,” the report says.