The partial shutdown of the federal government is over — at least for three weeks — since President Donald Trump and lawmakers agreed to reopen the government without the $5.7 billion request from Trump for a border wall with Mexico. But that hasn’t stopped Trump from repeating his takes on illegal immigration: that it’s rampant and comes at a staggering cost.

"We are not even into February and the cost of illegal immigration so far this year is $18,959,495,168. Cost Friday was $603,331,392. There are at least 25,772,342 illegal aliens, not the 11,000,000 that have been reported for years, in our Country. So ridiculous! DHS," Trump tweeted Jan. 27.

We are not even into February and the cost of illegal immigration so far this year is $18,959,495,168. Cost Friday was $603,331,392. There are at least 25,772,342 illegal aliens, not the 11,000,000 that have been reported for years, in our Country. So ridiculous! DHS — Donald J. Trump (@realDonaldTrump) January 27, 2019

Trump's numbers are precise to the point that one might think they are drawn from a report. But it’s unclear where they come from, and immigration experts and demographers refute related estimates.

Claim about cost of illegal immigration

We don’t know how Trump determined that the cost of illegal immigration "so far this year" is $18,959,495,168, or that the "cost Friday was $603,331,392."

Trump’s tweet ends with "DHS" — the acronym for the Department of Homeland Security, which is responsible for the enforcement of immigration laws. We asked DHS and the White House to provide the research Trump used for his claim. Neither presented information.

Last month, Trump claimed illegal immigration cost the United States $250 billion a year. We rated that False because even the highest estimates we found were nowhere near $250 billion.

The right-leaning Federation for American Immigration Reform (FAIR) estimated in a September 2017 report that the federal, state and local costs of more than 12.5 million people in the United States illegally was around $135 billion. After calculating this population’s tax contributions, the group said the total economic impact of illegal immigration was around $116 billion (up from $113 billion in 2013).

If Trump based his latest claim on the $250 billion annual estimate he used in December and divided that by 12 months, then he would arrive at about $20.8 billion a month cost, slightly higher than his "so far this year" estimate. But that’s not necessarily a precise way of calculating illegal immigration costs.

Trump regularly tweets about the cost of illegal immigration, and generally omits the basis for his numbers. On Dec. 4, 2018, he said the cost was $250 billion a year, about two weeks later, he said it was $275 billion a year. In 2016, he said it was $113 billion a year.

Claim about number of immigrants living in the United States illegally

Most estimates contradict Trump’s assertion that "there are at least" 25.7 million immigrants living in the country illegally. Widely accepted estimates say it’s closer to 11 million.

A December 2018 DHS report estimated that there were 12 million immigrants in the country illegally in January 2015. The report acknowledged estimates from two other sources, Pew Research Center and the Center for Migration Studies.

The three sets of estimates (from DHS, Pew, Center for Migration Studies) were "roughly similar," the DHS report said, but there were differences in the assumptions and specific methodologies, leading to "somewhat different numbers and trends."

The DHS report did not mention a September 2018 study from researchers at Yale University, which estimated there was an average of 22.1 million immigrants in the country illegally in 2016. A conservative estimate is 16.7 million, the Yale study said, with the high end at 29.5 million

The 11 million estimate derives from population surveys and legal immigration records; whereas the Yale estimate used an alternative approach "grounded in fundamental principles of demographic flows," the Yale study said.

Demographers and immigration experts have criticized the Yale study. Some say that it’s not adequately grounded in empirical research about illegal immigration patterns; that it significantly overestimates migration from Mexico; and that, if there are millions of additional people in the United States, then there would be more related demographic records, such as birth and school records for their children.

In a Jan. 27 CBS "Face the Nation" interview, acting White House chief of staff Mick Mulvaney couldn’t say where Trump got his estimate. The number has to be higher than 11 million though, Mulvaney said, citing illegal immigration numbers from the past three months.

"I'm not exactly sure where the president got that number this morning," Mulvaney said. "But I think what you see him trying to do is point out how silly this debate is."

Our ruling

Trump said, "We are not even into February and the cost of illegal immigration so far this year is $18,959,495,168. Cost Friday was $603,331,392. There are at least 25,772,342 illegal aliens, not the 11,000,000 that have been reported for years, in our Country."

The source of Trump’s claim is unclear. We asked DHS and the White House to back Trump’s statement, but neither provided studies or any other data to support it.

Trump previously falsely claimed that the cost of illegal immigration was $250 billion a year. Even the highest annual estimates we found were significantly lower than that amount ($116 billion, after factoring in tax contributions).

Most estimates say there are around 11 million immigrants in the country illegally. A recent study from Yale University researchers said a mean number was 22.1 million, but several demographers have pointed flaws in the assumptions and findings of that study.

Without evidence from Trump or his administration to back this statement, we rate it False.