The influx of foreign migrants to New York could cost the state $4.5 billion more than expected next year, Governor Hochul today warned.

Writing to President Biden, Hochul requested several types of federal aid, ranging from reimbursement for National Guard deployments to free MTA fares for migrants.

The governor did not mince words about the root cause of the still-developing crisis, which has seen roughly 100,000 people travel to the state. The federal government, the governor wrote, has a “direct responsibility to manage and control” the nation’s borders, and that New York had neither “capacity” nor “responsibility” to address the cause of the influx.

She has good reason to be concerned.

New York state government officially faces a $9 billion budget gap in the fiscal year beginning next April 1, and Hochul in January must present a plan to tackle it as part of her fiscal 2024 executive budget proposal. The governor had earlier this month estimated the state was looking at an extra $1 billion in migrant-related costs, on top of $2 billion already allotted. Her latest estimate, combined with other costs set to hit the state’s ledger, could force Hochul to tackle a $15 billion (more than 10 percent) shortfall between expenses and revenues (excluding federal aid and borrowing).

The added costs are even more problematic for New York City, which has a smaller budget and less flexibility to reduce spending as it tackles what Mayor Adams has estimated will be $12 billion in additional costs. The City’s financial problems risk becoming state government’s—and state taxpayers’—problems.

The rate at which migrants are arriving in New York has overwhelmed existing social infrastructure such as New York City’s homeless shelters. It remains to be seen how many people will effectively come under state or city care when that arrival rate abates—and how long they will stay in that care.

The continued uncertainty around that question, and the fact that New York must make significant spending cuts, will likely make next year’s budget the most difficult and acrimonious since the Global Financial Crisis.