Many stores expect to offer free government-issued N95 masks this week

White House officials pledged last week to make 400 million certified N95 masks available to Americans for free in an effort to shore up the nation's defenses against COVID-19. But consumers may have to shop around to get their hands on one. 

Major pharmacy chains said they expect to start distributing the free face coverings this week. The effort comes as public health experts encourage the use of higher quality masks, including N95 respirators.

Well-fitted N95 mask filter 95% of airborne particles, and KN95 masks offer a similar level of protection. Cloth masks, or any covering that does not fit properly, offer far less protection against COVID-19.