ALL ADULTS LIVING in Massachusetts will become eligible to get a COVID-19 vaccine beginning on April 19, Gov. Charlie Baker announced Wednesday. That does not mean, however, that everyone will be able to immediately get a shot, since getting a dose will depend on how much supply becomes available from the federal government.

“It will take time obviously for the vaccine to arrive here in Massachusetts and for everyone in these groups to get appointments and get vaccinated,” Baker said at a press conference Wednesday, after touring a vaccination site at the Shaw’s Center in Brockton.

As more states are beginning to further open eligibility for vaccines, Baker announced an age and job-based timeline for vaccinating the rest of the state’s residents.

So far, Massachusetts has been allowing vaccines for health care workers, people living and working in congregate care settings, anyone 65 and older, people with two or more medical conditions that put them at high risk of getting seriously ill from COVID-19, and teachers.

On March 22, vaccines will become available to residents 60 and older, and for certain workers who are essential or customer-facing. These include people working in restaurants, agriculture and food service, grocery stores, food pantries, the medical supply chain, transit, vaccine development, public utilities, sanitation, public health, the courts, and funeral homes. According to the state’s COVID-19 Command Center, there are 810,000 people in this category, including 450,000 due to age and 360,000 essential workers.

On April 5, people 55 and older will become eligible, along with residents with one medical condition that puts them at high risk for COVID-19. The conditions include asthma, cancer, chronic kidney disease, COPD, Down Syndrome, heart conditions, an immunocompromised state, obesity, pregnancy, sickle cell disease, type 2 diabetes, as well as smokers. Another 895,000 people are in this category – 465,000 due to age and 430,000 due to a medical condition.

On April 19, anyone over age 16 will become eligible to get a vaccine. This will make 2.55 million residents eligible.

The timeline adheres to what Baker laid out in December, which predicted that the general public would become eligible beginning in April, although Baker has shifted who belongs in which category. For example, he moved up educators ahead of other essential workers. His initial timeline also did not make people ages 55 to 65 eligible before the general population, but he said the change was made to prioritize those most at risk.

“There’s a very strong and important correlation between COVID and age, and we believe adding these groups by age will help us vaccinate more of our most vulnerable population faster,” Baker said.

The timeline also fits with President Biden’s comments that he will direct states to make every American eligible for a vaccine by May 1.

So far, Massachusetts has administered 2.6 doses of COVID vaccines. Within 24 hours, the state is on track to have fully vaccinated 1 million people. Baker said the goal is to fully vaccinate 4 million residents. Massachusetts has 6.8 million residents, but children under 16 are ineligible for the vaccines.

Massachusetts will continue to make appointments available at mass vaccination sites through its preregistration website, and people can also try to find appointments outside of that system, through health care providers and through pharmacies that get vaccines directly from the federal government.

As in the past, how quickly people can actually get the shots will depend on supply from the federal government. Baker said the state has been told that supply will increase as manufacturing ramps up of the three approved vaccines by Moderna, Pfizer, and Johnson & Johnson.

“We can only move as fast as the manufacturers produce vaccines, and thankfully production is picking up,” Baker said.

This week, Massachusetts got 170,000 first doses, including an unexpected 8,000 doses of the one-shot Johnson & Johnson vaccine. The Johnson & Johnson vaccine was only recently approved by the FDA, and a very limited supply is expected to be available through the end of the month.

In total, the state will get 316,000 total doses this week, counting first and second shots, plus an additional 116,000 doses sent directly from the federal government to pharmacies and community health centers.

Approximately 100,000 doses each will go to mass vaccination sites and hospitals, with smaller numbers going to community health centers (27,000), regional collaboratives and local boards of health (60,000), pharmacies outside of the federal program (8,500), and mobile clinics (19,000).

Baker said he is hopeful, based on recent calls with the federal government, that the supply will soon ramp up to “hundreds of thousands of doses,” with Johnson & Johnson expected to ship significantly more doses by late March or early April. He called the availability of a single-shot vaccine that does not need a deep freeze for storage “a really big deal” in terms of the ability to fully vaccinate more people.

The governor was not ready to say when he would end the state of emergency he declared on March 10, 2020, although he urged residents to remain cautious about the spread of the virus and continue to be tested if they have concerns about it. He said he intends to maintain the state’s testing infrastructure through the end of June.

Secretary of Health and Human Services Marylou Sudders also announced Wednesday that the state has received $27.4 million in federal funds to put toward a “vaccine equity initiative” to increase trust and acceptance of the vaccine and aid vaccine distribution in hard-hit communities. This will include $10.6 million to assist residents with transportation to appointments, language interpretation, and appointment registration. Additional sums will go toward running vaccination clinics through community health centers, local boards of health, and at community settings in hard-hit communities and among populations that are hard to reach.

Baker, 64, becomes eligible for a vaccine Monday. Asked when he will get his shot, the governor said he will preregister and “will see what happens.”