Everything you need to know about the influx of migrants to Mass.

Haitian immigrant Gigie Zaldo held her one-month-old baby, Atalinda Nefertari, at the Immigrant Family Services Institute in Mattapan on March 11.Suzanne Kreiter/Globe Staff

Since the Massachusetts emergency shelter system reached its state-imposed 7,500-family capacity in November, the state has been embroiled in debates over the locations of overflow shelter sites, distribution of aid and resources for migrants, and how long families should be allowed to stay in emergency shelters.

The crisis has brought immigration to the forefront of local politics, highlighting concerns about border security and, at times, pushing anti-immigrant sentiments to the surface.

Here’s what to know about the migrant crisis in Massachusetts.

What’s behind the crisis, and the influx of migrants?

Massachusetts has seen a surge of foreign migrants over the past year, many fleeing violence and political turmoil in their countries of origin.

The state Office for Refugees and Immigrants reported 11,633 new arrivals in the 2023 federal fiscal year, compared to 4,359 in 2022 and 1,018 in 2021. These numbers account for refugees and immigrants served by Massachusetts-based resettlement agencies who are eligible for federal support, so they don’t necessarily encompass all new arrivals to the state.

Several factors play into the influx, including a humanitarian parole program implemented by the Biden administration last year and the May 2023 expiration of Title 42, a pandemic policy that made it easy to quickly expel people who crossed the border without authorization.

The state’s shelters, which now house homeless and migrant families in nearly 100 communities around the state, are at full capacity, leaving some migrants and homeless families stuck on waitlists. In the meantime, the state has opened emergency overflow sites in areas including Fort Point, Roxbury, and Cambridge, to mixed reactions from neighbors.

Meshach Little of Northill Wilkston Security Firm walked the perimeter of the main living area at the state's new emergency overflow shelter for migrants at the Melnea A. Cass Recreational Complex in Boston.Craig F. Walker/Globe Staff

Meanwhile, those already living in shelters face barriers moving out of them. Often lacking the educational resources to learn proficient English, many face challenges obtaining work authorization, a difficult and slow-moving process in which applicants can gain eligibility to receive an Employment Authorization Document only after their application has been pending for 180 days.

Even after obtaining authorization, the task of finding work is often slow and ridden with obstacles.

“Without [migrants] learning English, without them getting better jobs, it’s going to be very difficult for them to exit the current housing and food places that they’re [in],” said Vince Rivers, executive director of the Immigrant Learning Center, a Malden-based nonprofit that provides English for Speakers of Other Languages classes to immigrant and refugee adults.

The migrant crisis is also, in part, a housing crisis, with the state facing difficulties reining in the cost of housing. The average stay at shelters has increased over the last 10 years.

Where are migrants coming from? How — and why — are they coming to Massachusetts?

According to data from the Office for Refugees and Immigrants, 72 percent of the state’s recent migrants come from Haiti, which has become engulfed by violence and chaos, with gang leaders rampaging around the capital, Port-au-Prince, and sowing unrest. Millions of Haitians are hungry and desperate as they face threats to their food supplies, clean water, and health care.

Most Haitian migrants are arriving in Massachusetts by plane, Rivers said, through the Humanitarian Parole Program for Cubans, Haitians, Nicaraguans, and Venezuelans implemented by the Biden administration last year.

The CHNV process allows 30,000 migrants per month from these four countries to enter the United States for a two-year period after passing a background check and securing a sponsor.

Many Haitian migrants are drawn to Massachusetts because of its long-established Haitian community. Massachusetts had the third-largest Haitian population of any state as of 2021, according to a recent Boston Indicators report. More than 50,000 Haitian-born residents were living in Greater Boston at that point, which preceded Haiti’s recent strife and the surge of migration that followed.

Despite the barriers upon US arrival, Rivers said the immigrants in his ESOL classes want to work.

“They can’t get to their own dreams without working,” Rivers said. “They don’t want to live in a shelter. They don’t want the free food. They want to have a family. They want to have a stable life. They want to have growth. They want to have their children do better than they’re doing.”

Pastor Dieufort Fleurissaint, aka "Pastor Keke," second from right, talked with a fellow Haitian, including Ernest Jean Pierre, center, about the resources available at the Equity Now & Beyond Resource & Wellness Clinic in the Roxbury neighborhood of Boston on March 14, 2024.Craig F. Walker/Globe Staff

How many migrants are currently living in Massachusetts shelters?

As of March 11, about half the families enrolled in the state emergency shelter system were migrant, refugee, or asylum-seeking families, a total of 3,775, according to Governor Maura Healey’s administration.

Those enrolled in the system are split between shelters and hotels or motels. Another 750 families were on the waitlist, as of March 11.

How has Massachusetts responded to the crisis?

A Massachusetts right-to-shelter law requires the state to offer shelter to homeless families and pregnant women. Although there traditionally is no limit on how long families can stay in shelters, the Massachusetts House recently passed a bill to impose a nine-month maximum stay for most homeless families. The legislation will now go to the Senate.

A $3 billion spending bill passed in December pumped $250 million into the emergency shelter system, with up to $50 million allotted towards the creation of overflow shelters.

At overflow sites, state officials and shelter providers have specifically sought out local businesses, including security firms and restaurants, to provide essential services for shelters.

The state has also run work authorization clinics for families staying in shelters and budgeted to reimburse school districts enrolling students from shelters.

In some towns and neighborhoods, residents have expressed frustration and concerns for new arrivals receiving shelter or aid in their communities, with anti-immigrant sentiments prompting an elevated need for security at some shelters.

Questions about whether the state has done enough to ensure the safety of vulnerable women and children at the shelters took on new urgency last week, after a 26-year-old man was charged with raping a 15-year-old girl at a Rockland hotel sheltering migrants.

Some communities have responded to the crisis with a range of surprise and sympathy, with some nonprofits and religious coalitions jumping to action to support migrants.

What’s the cost to the state?

Shelter program costs are expected to reach nearly $1 billion this fiscal year and another $1 billion in the next.

The House is weighing a supplemental spending bill Healey filed in January that seeks to drain a surplus budget account of nearly $900 million to continue sheltering homeless and migrant families both this year and next.

Her administration has projected the state will need $224 million more for the emergency shelter program before the end of the current fiscal year in June. Costs are then expected to reach an additional $915 million for the next fiscal year that begins in July. Even if lawmakers embrace her plan, Healey aides acknowledge the state would still fall $91 million short of covering the costs of the program for next fiscal year.

And with continued delays and barriers to obtaining work authorization that could allow migrants to earn enough to move out of shelters, the climbing costs don’t seem likely to stall.

What about the US government’s response?

The Biden administration continues to operate its humanitarian parole program for migrants from Cuba, Haiti, Nicaragua, and Venezuela.

Biden also proposed a $106 billion supplemental funding request last year that aimed to address immediate national security concerns, including $4.4 billion in funding for a federal migration strategy with $1.4 billion in aid to states and localities.

But the issue of immigration — and US border policies — remains contentious. Texas and 20 other Republican states challenged the CHNV program, but were dismissed by a federal judge earlier this month.

Republicans in Congress have made continual efforts to pass bills clamping down on immigration, including a bill passed by the House this month that would require federal authorities to detain unauthorized immigrants who have been accused of theft. As immigration becomes a top issue in the presidential election, Republicans are using nearly every tool at their disposal to condemn how the president has handled immigration.

Despite such efforts, it was GOP lawmakers who last month blocked a bipartisan border bill to tighten border restrictions and provide supplemental funding to Immigration and Customs Enforcement.

Material from the New York Times, Associated Press, and Washington Post wire services was included in this report.