BOSTON (SHNS) – Expecting Massachusetts to clear the “milestone” of 1 million people fully vaccinated from COVID-19 in the next 24 hours, Gov. Charlie Baker slotted the final pieces of the state’s vaccine distribution puzzle on Wednesday as he expects the federal government to increase supply in the coming weeks.

All residents age 16 and older will now be eligible to book an appointment for a COVID-19 vaccination by April 19, which in Massachusetts also happens to be a holiday – Patriots’ Day.

The schedule is in line with what the administration outlined in December before the first shot went into an arm, and beats President Joe Biden’s target of May 1 for states to lift all restrictions on vaccinations. It could still take weeks or longer, however, for newly eligible residents to get an appointment, with more than 3.8 million people still waiting to become eligible.

“The vaccines can’t come fast enough,” Baker said.

Baker, who visited a Brockton vaccination site on St. Patrick’s Day, said he and other governors had been given assurances by the White House on Tuesday that “the supply chain will continue to open up” at the end of March and throughout April, delivering hundreds of thousands of additional doses.

Massachusetts received a small increase of about 20,000 first doses this week, meaning 170,000 first doses will be disseminated for use next week.

“The projection the feds put out on the call yesterday, especially with respect to (Johnson & Johnson) were really encouraging both for the end of March and for the month of April,” Baker said. The governor reached out to other governors after the call to make sure “they all heard the same thing.”

“The news about the arrival of more vaccine from the federal government means we will be able to move faster to get doses to our residents, and this is long overdue and welcome. We are all eager to get back to something like normal, and see our friends and loved ones again,” Baker said.

The governor for weeks has been blaming supply for the pace of vaccinations, but said the message from Washington means the state can move forward with the final stages of its vaccination program. Beginning next Monday, people 60 and older and certain workers, including restaurant employees, transit workers, retail and grocery store personnel, will be eligible to book a vaccine appointment.

People 55 and older or with one underlying health condition will become eligible April 5, and the program opens to the general public April 19.

The timeline means Baker, 64, will become eligible himself for a vaccine next week.

“I plan to pre-register and we’ll see what happens. Because I will be eligible. I’m very excited about that,” he said.

The announcement was made in the wake of a new poll showing Baker’s approval rating on the decline, and it came days ahead of his plans to testify on Tuesday for the second time before the Legislature’s Joint Committee on COVID-19 and Emergency Preparedness, where lawmakers are expected to probe his decision to use private contractors to run mass vaccination sites instead of relying more on local boards of health.

Rep. William Driscoll, the House chair of the committee, said Baker should use the time between now and when supply ramps up to test the capacity of regional vaccine collaboratives, many run by local providers and boards of health.

“I agree that pressure testing now via increased allocation to RCs helps on multiple levels,” Driscoll tweeted.

Benjamin Downing, a former state senator and Democratic candidate for governor, also welcomed the news, but suggested that “untold suffering, anger, frustration, and fear” could have been avoided if the administration planned better and had not relied on “trial-by-error governance.”

“Today’s plan brings overdue relief to Massachusetts families searching for clear and steady guidance from their Governor. Along with pre-registration, expanded eligibility and increased resources towards equity are good developments that will help remedy the countless missteps in our vaccine rollout,” Downing said.

The rollout has been dogged by questions about the governor’s prioritization decisions and technical problems but also hampered by the lack of available doses flowing to the states from drug companies and the federal government. A recent UMass Amherst poll found support for the job Baker is doing as governor eroding since the summer, down from a high of 78 percent in August to 52 percent in March.

But after a slow start, Massachusetts has become a leader in doses administered per capita, ranking first among states with at least 5 million residents, and Baker said the state’s ranks second in vaccinating Black residents, at 16 percent.

“Practically no other state in America is moving as quickly as we are, and as equitably as we are here in Massachusetts,” Baker said.

Sudden tweaks made to the vaccine plan over the past few months — such as the late addition of a call center, pre-registration capability and the addition of asthma to the list of qualifying health conditions — have earned him criticism from many Democrats on Beacon Hill for the lack of predictability.

Brockton Neighborhood Health Center CEO Sue Joss, however, described the administration as “nimble” and willing to adjust when things aren’t working.

“I have to say we have the best governor in the country for managing this crisis,” Joss said as she introduced the governor at the press conference.

To improve equity in vaccine distribution, Health and Human Services Secretary Marylou Sudders said the state had received a $27.4 million grant from the Centers for Disease Control and Prevention that would be used to build trust and vaccine acceptance in the state’s 20 hardest-hit and diverse communities.

Of that new funding, $5.1 million will go to community health centers and $4.7 million will go straight to those 20 municipalities to support vaccine clinics. Another $4 million will be awarded for vaccine outreach and education through grants to community and faith-based organizations, and $10.6 million will be used for appointment registration assistance, transportation to clinics, mobile vaccination units and other supports.

Sudders said the final $3 million will be deployed to qualified organizations positioned to help vaccinate the homeless, migrant farmers, undocumented immigrants and the LGBTQ community.

Massachusetts Health and Hospital Association President President Steve Walsh said the group “fully supports” the timeline outlined by Baker on Wednesday and hospitals are “well equipped to carry out this timeline for eligibility.”

“As residents prepare to get vaccinated, the message from our healthcare leaders is simple: the vaccines are safe, they are effective, and they are our single best chance at putting COVID-19 behind us,” Walsh said.

Of the nearly 7 million residents of Massachusetts, more than 5.5 million were over the age of 16 in 2019, according to the U.S. Census Bureau.

As of Tuesday, 946,306 people had been fully vaccinated with either two doses of the Pfizer and Moderna vaccines or one dose of the Johnson & Johnson vaccine, and a total of 1.73 million had received at least the first or only dose of vaccine they will need.

Baker said the goal is to fully vaccinate 4 million residents as quickly as possible, which would be over 70 percent of the adult population.

“It would be great to have more but when you get to the point where 4 million people have been vaccinated and 560,000 people had the virus, and hopefully once you get to that point almost everybody knows somebody who has been vaccinated, and hopefully that will convince some of the late arrivals to just do it,” Baker said.

Sudders said that for use as first or second shots next week the state will distribute 101,890 doses to mass vaccination sites, 99,230 doses to provider groups, 27,450 doses to community health centers, 40,370 doses to regional collaboratives, 19,201 doses to local boards of health in “equity communities,” and 19,180 doses for mobile clinics that offer vaccines for residents of long-term and congregate care facilities, affordable senior housing and homebound residents.

Pharmacies will also receive 8,490 doses from the state’s allotment in addition to the 106,440 doses CVS Health and others receive directly through the federal retail pharmacy vaccine program.