State lawmakers adjourned early Thursday morning without a deal on a $2.8 billion spending bill, leaving millions of dollars meant to shore up the state’s overburdened shelter system hung up in private negotiations.

Top Democrats in the House and Senate both said they hope to reach a compromise by January. But by pushing their talks past Wednesday, they make that a heavier lift — from now until Jan. 3, 2024, legislative rules stipulate that the two branches can meet only in informal sessions, where any one lawmaker can block a bill.

“We're very disappointed. There's a lot of important work and important appropriations that we are committed to getting done,” Senate budget chief Michael Rodrigues told reporters around 1 a.m. “We have collective bargaining agreements. We have money for a lot of important things, providing additional resources for the humanitarian crisis relative to the migrants. Our goal was to get it done tonight, but we just weren't able to, so we'll pick it up again tomorrow. We're not going to give up.”

The bill features money for the MassHealth program, raises for state workers and $250 million for an emergency shelter network that has been pushed to capacity by both an influx of newly arrived migrant families and longer-term Massachusetts residents struggling to afford housing.

Republicans in both branches voted against the bill after raising concerns with the state’s response to the shelter crisis, and could opt to derail a deal if one emerges this year.

Rodrigues, a Westport Democrat, said he was “confident” the Senate could secure the unanimous vote it would need to pass a final bill.

Asked if the House would be able to get a bill through in informal sessions, Speaker Ron Mariano said, “Yeah, I think we can.”

“The Republicans are on record of having voted against this,” he said. “So whether or not they need another vote is still open to discussion, and we will talk to them about that.”

While both branches included the $250 million in shelter money, they diverged on how, specifically, it should be spent.

House lawmakers wanted to define a framework for how the Healey administration could spend the money. In response to Gov. Maura Healey’s decision to cap shelter capacity at 7,500 families, the House bill carves out $50 million for the state to stand up at least one emergency overflow site for waitlisted families — and calls for the cap to be revoked if the Healey administration does not launch at least one overflow site within 30 days of the bill being signed into law.

“We just want to prevent people from sleeping in the streets or sleeping in our airports or sleeping in our train stations,” House budget chief Aaron Michlewitz said.

Senators, meanwhile, said they wanted to give Healey and her team flexibility to respond as the situation evolves. Their bill would allow the administration to put some of the $250 million toward overflow sites, but would not require it.

Rodrigues and Michlewitz traded proposals throughout the day Wednesday. After midnight, the two sides agreed they were too far apart to finalize an accord that evening and formally tapped a six-lawmaker committee to continue closed-door talks past Thursday.

Anti-homelessness advocates waited in the State House hallways as the 13-hour session dragged on, hoping to see the shelter money approved.

After lawmakers adjourned, Kelly Turley of the Massachusetts Coalition for the Homeless said she was “concerned for families tonight who have been placed on a waiting list and don't have a place to stay.”

“Passing the supplemental budget, including language to ensure that there are overflow spaces for families who've been deemed eligible for emergency assistance shelter and put on a waiting list is critical,” she said. “We hope that the House and Senate can swiftly come to agreement and make sure that the needs of families and children are primary.”