The migrant crisis is more costly than Americans realize.

Last year, US taxpayers shelled out some $150 billion in government services and support to help the 20 million illegal migrants in the country, according to a study from the Federation for American Immigration Reform (FAIR).

And most of the cost is being borne by state and local governments.

In Massachusetts, Republican leaders say there’s a $1 billion hole in state coffers — and they’re accusing the Democrat-controlled government of quietly siphoning off tax dollars to deal with the migrant crisis.

On Tuesday the state’s Republican party filed a Freedom of Information Act request demanding Gov. Maura Healey release Massachusetts’ full migrant budget, and alleging that the true cost has been hidden from the public.

“The Healey-Driscoll Administration has shrouded nearly $1 billion spent in secrecy, leaving Massachusetts residents in the dark,” MassGOP Amy Carnevale told Fox News.

“They have withheld critical information on 600 incidents involving police, fire and EMT. Blocking journalists at every turn, the administration has obstructed the flow of information to the public.”

But, FAIR estimates that in 2023 alone the cost in state services to account for the illegal migrants and their children in the Bay State was closer to $3 billion.

In New York, the comptroller estimated that the migrant crisis will cost state taxpayers $4.3 billion through 2025, and New York City taxpayers $3 billion in fiscal year 2024 alone.

However, according to FAIR’s estimates, the estimated 1.45 million illegal migrants and children in the state already cost taxpayers nearly $10 billion in 2023.

While most states’ accounts of migrant expenses focus on emergency housing and aid, FAIR’s assessment factored in the full breadth of state services they draw on while in the US.

Services like education, medical expenses, law enforcement, legal costs, and welfare, were prominent factors FAIR looked at in their study.

Those, coupled with the differences in tax revenue compared to expenses, helped contribute to the discrepancies between state reporting and the estimated true cost of hosting migrants.

FAIR also included the costs of US-born children of illegal immigrants – something many reports don’t factor in.

“As long as we keep allowing millions of people to come into the country illegally every year, it’s obviously going to continue to increase the costs,” FAIR spokesperson Ira Mehlman told The Post.

“This seems to be just sort of basic, common sense. If you were going to be bringing in lots and lots of people, many of them working off the books for very low wages, that there are going to be enormous social costs incurred,” he added.

And not a single state across the country has been spared – FAIR projected West Virginia spent the least, with costs to care for migrants and their children totaling still more than $33 million.

But that’s just one of seven states that coughed up less than $100 million for the crisis.

Half of US states were estimated to have shelled out in excess of $100 million, while the bill for 19 reaches well over $1 billion.

California led the country with expenses of nearly $31 billion to take care of illegal immigrants and their children, according to FAIR’s study.

Texas followed at more than $13 billion; Florida clocked in at more than $8 billion; then New York and New Jersey.

The total outlet by American taxpayers was even higher, according to estimates from FAIR, at $182 billion.

However, illegal migrants do pay taxes — and FAIR estimated their contributions to local, state and federal treasuries was about $32 billion.

However, that still left $150 billion in costs saddled that American taxpayers were saddled with, FAIR estimated.

“The argument that illegal aliens pay more in taxes than they use in services, it’s completely misleading,” Mehlman said.

The staggering costs to taxpayers have ballooned since about 2017, when the true price of illegal immigration was estimated to be about $116 billion, according to FAIR.

That means the cost to US taxpayers rose about $35 billion in just five years, FAIR found.

More than 1.3 million people were released into the US by Customs and Border protection between March 2023 and July 2024 – not including the scores who slipped in undetected, known as “gotaways.”

“It’s an atrocity to spend taxpayer money to support and help people that don’t even have the lawful right to be here because the federal government has got policies in place that are allowing this to occur,” said Chris Clem, former Border Patrol chief of the Yuma sector in Arizona.

“This is another pull factor because all they have to do is get arrested, turn themselves in and get released. They are getting opportunities that you and I don’t get.”