Reopening swaths of public life in Massachusetts will play out across four distinct phases and involve new widespread and mandatory safety regulations for all businesses.

The approach, announced by the Baker administration on Monday, could launch as as soon as next week with an initial phase applying to businesses that are best able to limit the type of person-to-person contacts that have fueled the ongoing COVID-19 pandemic.

The broad-stroke framework that Gov. Charlie Baker and Lt. Gov. Karyn Polito outlined would ease forced shutdowns of non-essential businesses gradually over a timeline yet to be determined, building up to a "new normal" once a vaccine or other treatment for the highly infectious disease is available.

Many details about the process are still in the works and will depend on the recommendations an advisory panel will file in one week and on the trajectory of trends in the state's COVID-19 outbreak. If public health data shows a new spike in cases or increased risks, the administration could order a return to an earlier phase.

"The goal is to begin this process around May 18, but it will be gradual and facts on the grounds will determine if we actually hit that goal," Baker said at a press conference, noting that Massachusetts has been "one of the hardest-hit states." "That means we have to be flexible and honest about the fact that the timing and the details of these phases could change depending upon the track the virus takes."

The virus has taken a huge toll already, causing thousands of deaths, forcing businesses to close and people to make sacrifices, and sending hundreds of thousands of residents into the ranks of the unemployed.

Since its launch on April 28, the reopening advisory board that Polito and Economic Development Secretary Mike Kennealy are leading has been busy. It has met with 44 industry associations and community coalitions and has received written comments from more than 2,200 organizations or employers.

All employers in Massachusetts will be required to follow a set of safety standards unveiled Monday. Officials hope the stricter requirements -- which cover hygiene, cleaning, social distancing and business operations -- will lower the risk of coronavirus spread and stave off a potential second surge in cases.

To comply with the standards, every business must ensure customers, employees and vendors are at least six feet apart "to the greatest extent possible." Employees must wear face coverings or masks and wash their hands frequently, and employers have to ensure disinfection of all shared or frequently touched surfaces "at intervals appropriate to said workplace."

Any workers who display COVID-19-like symptoms should not report to work, the regulations order, and if any employee is diagnosed with the illness, the employer must conduct a round of cleaning and disinfecting.

The administration will also develop additional industry-specific requirements and best practices, likely published in the May 18 report from the panel drafting a roadmap for the phased reopening.

"Part of the reason why the reopening advisory board felt it was important to establish not just industry-specific guidance, but a set of criteria that we're going to apply to all employers, is so that it becomes, for all intents and purposes, something people think of as standard operating procedure," Baker said.

On the economic front, pressure is growing. The national unemployment rate jumped to 14.7 percent in April, the largest one-month increase on record, and experts believe Massachusetts has an even higher rate.

Non-essential businesses in Massachusetts have been shuttered since March 23 in an attempt to blunt the spread of the novel coronavirus. Baker's executive order requiring those closures expires May 18.

Phase one, which the administration titled "Start," could begin on or around that May 18 date. Officials have not yet published a list of what workplaces will get the green light to resume modified operations, and Baker said Monday that those best able to limit face-to-face interaction will be at the top of the list.

"As we move towards a new normal, we all have a lot of work to do," Polito said. "I am confident that when we reopen, we will do so in a safe manner for all the people of this commonwealth."

It is not clear when the state will move to phases two through four -- broadly dubbed "Cautious," "Vigilant" and "New Normal," respectively -- but Baker and Polito said the transitions will depend on whether key data indicators continue positive trends.

Asked how long each phase would last, Baker said other states have embarked on similar plans with stages ranging between three and four weeks and that Massachusetts will "probably work off a similar model."

"There isn't going to be a hard and fast on a lot of this," he said. "People are going to want to see what happens, because for everybody, this is a new experience."

Non-emergency child care facilities are required to stay closed until June 29 under Baker's orders, and the availability of those services is essential to support working parents.

"That's going to end up being part of the conversation as well, and that one will absolutely be phased, because there are a lot of issues there that have to get worked through," Baker said Monday when asked about daycares.

Working groups within the Baker administration are focused on next steps on testing and tracing, outdoor recreation, higher education, transportation and child care. Gov. Baker says those conversations are "crucial" to decision-making on the economic reopening.

Steps toward reopening come as data shows Massachusetts is trending favorably on some key measures.

The number of patients actively hospitalized for COVID-19 dropped from 3,965 on April 21 to 3,102 on Sunday, according to Department of Public Health data published Monday. New tests are coming back positive less frequently than they were a month ago, with only 9 percent of tests reported Sunday and 11 percent reported Monday confirming cases.

Overall cases and fatalities are still increasing, though, and the death toll surpassed 5,000 on Monday with another 129 newly reported deaths bringing the total to 5,108.

At his press conference, the governor said he was "incredibly heartened" to see progress in western Massachusetts, which suffered a sharp impact in the outbreak's earlier days, but reiterated the importance of a "sustained trend" before committing to a change in approach.

Tracking COVID-19 infections will play an important role in the transition out of crisis, Baker said, forecasting a "pretty significant growth in testing through the fall." He said he would offer more details on how testing will be deployed, including use of antibody testing, "when the package is fully developed."

"We certainly expect that testing has a major role to play in what happens going forward," he said. "The antibody piece has a role to play, too, but I think we would say for what people are saying it can do and how it can fit in, it has work to do."