(CNN)More states have mandated the use of masks and face coverings while in public.
After states lifted some coronavirus restrictions, an uptick in cases has led to new restrictions in many, The number of cases is rising in more than half of them.
That's where masks come in. A recent study found that the use of masks and face coverings has been the most effective way to reduce person-to-person spread of coronavirus.
Here are the states that require the use of masks or face coverings in public settings.
As of July 15:
Gov. Kay Ivey issued an amended Safer at Home order which requires residents to wear a mask or face covering when in public and in close contact with other people. It remains in effect until July 31.
As of July 20:
Gov. Asa Hutchinson announced that beginning on Monday, July 20, residents 10 years and older must wear masks when in the presence of non-household members and aren't able to socially distance. The order is enforceable and offenders can be cited for a misdemeanor or fined.
As of June 18:
Gov. Gavin Newsom issued a statewide order requiring the use of face coverings in public indoor spaces, including while shopping, riding on public transportation or seeking medical care.
Newsom's order also mandated the use of masks or face coverings in public outdoor spaces when social distancing is not an option. There was no guidance on how the order will be enforced or if violators will face any penalties or citations.
As of July 17:
Gov. Jared Polis announced that residents will be required to wear masks when in public indoor spaces and not able to socially distance from others.
As of April 20:
Connecticut's mask requirement applies to any resident over the age of 2 in a public space where social distancing isn't possible. The rules also apply to individuals using public transportation, taxis or rideshare services.
The state's Department of Economic and Community Development also released mask guidelines for essential workers:
Employees at essential businesses must wear masks or any other material covering their mouth and nose at all times while at work. Employers must provide masks or the materials to make them. All customers under age 2 must wear them, too.
People who refuse to wear masks aren't required to provide proof that they're medically exempt.
As of April 28:
Gov. John Carney ordered residents to wear face masks while in public, including at grocery and convenience stores, pharmacies, doctor's offices and on public transportation.
Children under the age of 12 are not required to wear face coverings, and those age 2 and under must not wear face masks due to the risk of suffocation.
District of Columbia
As of May 16:
Mayor Muriel Bowser ordered the use of masks or face coverings when conducting essential business or travel and social distancing isn't possible.
Masks or other face coverings are required in grocery stores, pharmacies and takeout restaurants. On public transportation, face coverings are required if individuals are unable to be six feet apart.
Children between the ages of 2 and 9 are advised to wear masks.
As of April 20:
Both customers and employees at essential businesses are required to wear cloth face coverings. Establishments must limit the number of customers allowed in and keep them six feet apart.
Anyone who violates those rules could face a fine of up to $5,000, or up to a year in prison if found guilty, according to Hawaii Gov. David Ige's order.
As of May 1:
Gov. J.B. Pritzker ordered the use of face masks for anyone stepping outside their house.
Face coverings are required while shopping at essential businesses, traveling on public transportation, picking up food, or visiting the doctor and it's impossible to stay six feet apart.
As of July 27:
Gov. Eric Holcomb announced that a statewide mask mandate will go into effect on July 27 due to the increase in the state's positivity rate and some counties seeing increases in cases.
The mask mandate applies to anyone who is 8 years and older, and is required in indoor public spaces, commercial entities, while using transportation services and outdoors where social distancing isn't possible.
The mask mandate will remain in effect indefinitely.
As of July 3:
An executive order was issued by Gov. Laura Kelly mandating face masks must be worn statewide in public spaces.
Kelly, commenting on Facebook Monday, wrote, "Starting July 3, I will issue an Executive Order requiring marks be worn in indoor public spaces, and at any outdoor gathering in which social distancing cannot be maintained. This step will keep Kansans healthy, and keep Kansas open for business."
As of May 11:
Gov. Andy Beshear ordered all state residents to wear face masks in public.
Beshear has said that people will not be fined or arrested for not wearing a mask in public, but the order gives businesses the right to turn away any customer not wearing a face covering.
As of July 13:
Gov. John Bel Edwards announced a statewide mask order for everyone 8 years and older.
Parishes in the state can opt out of the mask mandate if they don't have a high positivity rate, but Edwards said only three would qualify to do so right now.
As of May 1:
Gov. Janet Mills issued an order requiring face coverings or masks for anyone over the age of 2 in indoor public spaces such as supermarkets, retail stores, pharmacies and doctor's offices.
As of April 18:
Commuters must wear face coverings while using Maryland's public transit, according to Gov. Larry Hogan's order.
Employees of essential businesses and customers over the age 9 must wear face coverings. Adults accompanying young children should make an effort to get them to wear a mask.
Children under the age of 2 do not have to adhere to this order.
As of June 18:
Michigan requires all residents to wear face coverings or masks in all public settings.
Businesses are allowed to deny entry to individuals not wearing face coverings.
As of July 25:
Gov. Tim Walz has issued an executive order that requires the use of masks in indoor public places, while using public transportation and while outdoors where social distancing isn't possible. Children under the age of 5 are exempt from the mask mandate.
As of July 16:
Face coverings are now required in certain indoor business settings for counties with four or more active Covid-19 cases, according to a new directive issued by Montana Gov. Steve Bullock (D). Residents attending outdoor gatherings of 50 or more people when social distancing isn't possible will also require face coverings.
As of June 24:
Nevada requires anyone in any public space to wear a mask. Nevada Gov. Steve Sisolak's office said this includes while using public transportation, in public facing work environments, while patronizing businesses, or interacting with others in any generally publicly accessible space.
"For Nevada to stay safe and stay open, we must make face coverings a routine part of our daily life," Sisolak said.
As of April 8:
New Jersey was the first state to require customers and employees to wear face coverings at essential businesses and construction sites. Businesses must provide them to employees and deny entry to any customer who refuse to wear them (though customers can still pick up food or medicines in other contact-free ways).
Commuters on New Jersey's trains, buses and light rails must wear face coverings. If they refuse, they may be denied entry.
As of May 16:
Adults are required to wear masks in all public settings, except while eating, drinking, exercising or for medical reasons. Masks are recommended for children 3 and older, and children 5 and under must have adult supervision.
As of April 17:
Gov. Andrew Cuomo's executive order mandated state residents to wear masks in public.
All residents over age 2 must wear masks or face coverings when in public and social distancing is impossible.
As of June 26:
Gov. Roy Cooper requires that face coverings be worn whenever people are out and about in public and where physical distancing is not possible. A number of businesses, such as restaurants and hair salons, also will require both employees and customers wear face masks.
"We need to all work together so we can protect our families and neighbors, restore our economy, and get people back to work and our children back to school," Cooper said in announcing the requirement.
As of July 23:
Gov. Mike DeWine announced during a news briefing that there will be a mask mandate that requires people to cover their nose and mouth when inside public spaces or outside when social distancing is not possible.
As of July 1:
Gov. Kate Brown has now required the state's residents to wear face coverings in all indoor public spaces beginning July 1. Face covering requirements are already mandated in eight counties but this would broaden the mandate to the whole state.
"If you want your local shops and restaurants to stay open, then wear a face covering when out in public," she added.
As of April 19:
Essential businesses must provide and require their employees to wear masks, according to the order from Pennsylvania's Department of Health. Customers at these businesses must wear masks while on the premises or be denied entry.
People are required to wear face coverings when in public spaces. Businesses must ensure customers are wearing face coverings.
As of May 8:
Gov. Gina Raimondo issued an order requiring all residents over the age of 2 to wear face coverings or masks while in public settings, whether indoors or outdoors.
As of July 3:
Gov. Greg Abbott issued an executive order that will require residents in counties with 20 or more active Covid-19 cases to wear face coverings in public. It takes effect midday on July 3.
The order says that failure to comply could be punishable by a fine.
As of May 29:
Gov. Ralph Northam instituted a statewide mask mandate that requires residents aged 10 and older to wear a mask when entering or spending time in establishments such as restaurants, grocery stores and train stations.
As of June 26:
Gov. Jay Inslee instituted a mask mandate that requires everyone to wear a mask or face covering in an indoor public space and in outdoor public spaces where social distancing isn't possible.
As of July 6:
Gov. Jim Justice issued an executive order that he said would require all West Virginians 9 years old and up to wear a face mask anytime they are in public and indoors and where they are unable to maintain six feet of social distancing.
Justice said he issued the order after the state experienced its highest daily total of new cases over the July 4th weekend.
"I know it's an inconvenience, but it's not going to be much of an inconvenience," Justice said. "If you don't decide to wear the face covering for yourself, if you don't decide to wear it for one of your loved ones or your friends, do it for the 95 West Virginians that have died, do it for the 95 people that we've lost."
CNN's Sarah Aarthun, Stephanie Becker, Roxanne Garcia, Shaina Negron, Nakia McNabb, Hollie Silverman, Konstantin Toropin, Shawn Nottingham and George Wehby contributed to this report. Map by Renee Rigdon.