The C.D.C. releases new guidance that will allow localities to ease masking and social distancing.

The Centers for Disease Control and Prevention on Friday offered a new strategy to help communities across the country live with the coronavirus and get back to some version of normal life.

The new guidelines suggest that 70 percent of Americans can now stop wearing masks, and no longer need to social distance or avoid crowded indoor spaces.

The recommendations no longer rely only on the number of cases in a community to determine the need for restrictions such as mask wearing. Instead, they direct counties to consider three measures to assess risk of the virus: new Covid-related hospital admissions over the previous week and the percentage of hospital beds occupied by Covid patients, as well as new coronavirus cases per 100,000 people over the previous week.

Based on these three factors, counties can calculate whether the risk to their residents is low, medium or high, according to the agency, and only areas of high risk should require everyone to wear a mask. But unvaccinated people should wear masks even in low-risk areas, the agency said.

Universal masking in schools had been endorsed by the agency since July, regardless of virus levels in the community, but the new guidelines recommend masking in schools only in counties at high risk.

The new guidelines are being released as the coronavirus is in retreat across the country. Case numbers have dropped to levels not seen before the surge of the Omicron variant, and hospitalizations have been plummeting. About 58,000 people are hospitalized with Covid nationwide, but those numbers have fallen by about 44 percent in the past two weeks.

Several experts said the new guidelines were appropriate for the country’s current situation. Although the number of cases nationwide is still high, “we’re well past the surge,” said Linsey Marr, an aerosol scientist at Virginia Tech. “We don’t need to be operating in emergency mode anymore.”

But many places have already shed pandemic restrictions. Most states have eased rules for mask-wearing, and some, like New Jersey, have announced plans to lift mandates even in schools. Others are poised to end indoor mask mandates in the coming weeks. An official recommendation from the C.D.C. may hold some sway in districts that have been more cautious.

Under the C.D.C.’s previous criteria, 95 percent of the counties in the United States were considered high risk. Using the new criteria, fewer than 30 percent of Americans are living in areas with a high level of risk, the agency said.

The new set of guidelines gives people a framework for adapting precautions as virus levels change, Dr. Rochelle P. Walensky, the C.D.C.’s director, told reporters on Friday.

“We want to give people a break from things like masking when our levels are low, and then have the ability to reach for them again should things get worse in the future,” she said. “We need to be prepared and we need to be ready for whatever comes next.”