https://www.politifact.com/truth-o-meter/statements/2019/jan/28/donald-trump/fact-checking-donald-trumps-claim-cost-illegal-imm/
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.