On Tuesday, July 27, 2021, the Centers for Disease Control and Prevention ("CDC") updated its public health recommendations for fully vaccinated people to recommend that fully vaccinated individuals resume wearing masks in public indoor settings in areas of "substantial or high transmission." The revised guidance is in response to surges in infection rates and hospitalizations in several regions across the country caused by the Delta variant.

While the CDC guidance is not a legal requirement unless state or local orders adopt it, some local governments have already initiated mask mandates, such as Los Angeles County, California, and St. Louis, Missouri, and more are expected to follow suit.

So What Areas Qualify as "Substantial or High Transmission" Zones?

The simple answer is that almost 2/3 of the counties in the entire country (63.45%) are at either the High or Substantial transmission level, and the trend towards High transmission level is increasing rapidly. The following CDC chart provides a helpful overview of the current numbers:

Level of Community Transmission


Number of U.S. Counties at this Level


Percent of U.S. Counties at this Level


Percentage Point Difference Since 7 Days Ago


































The levels are determined by total new cases per 100,000 persons in the last 7 days, and the percentage of tests that are positive within the past 7 days. The CDC has provided a detailed description of the levels, and an interactive map to allow individuals and businesses to determine whether they are in a High or Substantial transmission level area.

So what does this mean for your business?

As an initial matter, it is important to note that the CDC guidance applies to individual behaviour, and does not impose any obligations on businesses to require masks for employees or visitors. However, in some cases that are regulatory and/or other reasons why you may want to consider mandatory mask policies.

  1. As noted above, some areas have instituted mask mandates already, and more are expected over the coming days and weeks. You should review the state, county, and municipal COVID regulations that apply to each of your facilities, and make sure that you stay current, since as the last several months have taught us, things change.
  2. Instead of issuing their own orders, some states have chosen to expressly adopt the CDC's COVID guidance generally as the guidance that applies to businesses. You should therefore determine whether any of the jurisdictions where you operate have expressly adopted the CDC guidance and made it mandatory.
  3. Even if state, county, and local orders do not expressly require vaccinated individuals to wear masks, businesses are typically allowed to adopt policies that are more protective, so you should consider whether a mandatory mask policy is something that you want to implement.


The CDC has urged people to get vaccinated, "noting that the rise of cases and hospitalizations is greatest in places with low vaccination rates and among unvaccinated people." However, regardless of your vaccination status, it may be time to dig your facemask out again.

BCLP is carefully monitoring COVID-19 regulations and orders across the country, including the CDC guidance. Our COVID-19 Reopening Team would be happy to discuss any questions regarding your particular business.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.