Gov. Janet Mills speaks at an event in the Hall of Flags at the State House in Augusta earlier this month.

Maine is expected to see tens of millions of dollars in extra state revenue, and the governor proposed Tuesday to put $20 million of the money into the rainy day fund.

Democratic Gov. Janet Mills released her latest budget proposal Tuesday. It includes $5.5 million to school and community-based opioid programs and $20 million to a state fund providing no-interest loans for school repairs.

She also proposed setting aside $15 million to help repay federal funds regulators say the state improperly used on Riverview Psychiatric Center for years while it lacked federal certification.

Mills’ latest proposal follows a recent estimate by revenue forecasters that Maine’s revenues will exceed previous estimates by $66.7 million through June, thanks in part to a one-time bump in corporate tax revenue. Maine could also see an additional $20.7 million in fiscal years 2020 and 2021, and $33.1 million in 2022 and 2023.

“This change package prioritizes pressing investments needed to protect children’s safety, to repair crumbling schools, to pay back the previous administration’s debt, and to save money in the event of an economic downturn,” Mills said.

Her latest proposal would also involve hiring 62 new staff members — an 8 percent increase — for the Office of Child and Family Services, which has faced scrutiny in recent years following the death of two girls who allegedly died from child abuse. Mills calls for hiring 43 caseworker staff, six staffers in the agency’s background check unit and 13 intake staff members.

The governor said her plan for a new mental health unit would save the state money in the long run.

She plans to open a unit at Dorothea Dix Psychiatric Center for people in need of acute psychiatric care, including those deemed incompetent to stand trial and those transferred by jails. Maine’s previous Republican governor had proposed housing such individuals at a facility run by private contractors.

The latest proposal adds $2.85 million overall to Mills’ original $8 billion, two-year budget, according to her office. The governor’s office said her latest proposal leaves $16.5 million in surplus revenue available for lawmakers who have faced hundreds of bills this year.

That’s an 11 percent increase over the two-year, $7.2 billion budget that runs through June.

Lawmakers are still working on Mills’ budget proposal. The Legislature hopes to finish its work in coming weeks.

The budget needs buy-in from Republicans, who criticized the budget as too high of a starting point. Such critics have previously called for more money to Maine’s rainy day fund.

Meanwhile, some liberal groups have urged lawmakers to repeal tax cuts benefiting the wealthy to fund new spending proposals, including more school funding. Democrats on the Legislature’s taxation committee have expressed support for raising taxes to fund property tax relief.