Masks will once again be required indoors in Montgomery County starting Saturday — the latest development in a saga of flip-flopping mask policies.

The return of the mandate follows seven consecutive days of “substantial” transmission in the county, per the Centers for Disease Control and Prevention’s metrics. According to the CDC, “substantial” transmission occurs in a locality that reports between 50-100 new COVID-19 cases per 100,000 residents over the past seven days, or is currently reporting a positivity rate between 8% and 10%.

As of Tuesday, Nov. 16, the county recorded its seventh day of substantial spread, reporting a case rate per 100,000 residents of nearly 60. Current CDC guidance recommends that all individuals, regardless of vaccination status, wear a mask in indoor public settings in a locality that is experiencing either high or substantial spread — thus the return of the county’s mask mandate.

It won’t go into effect until Saturday, in order to give residents and businesses four days to prepare.

The indoor mask mandate lifted originally in late October, after the county achieved seven consecutive days of “moderate” transmission. The confusion started just days later, when rising case counts were poised to bring the mandate back, less than a week after it ended. At the time, transmission only needed to reach the “substantial” benchmark for one day — not sustained over seven days.

On Nov 2., the Montgomery County Council approved new rules for what would trigger or end the mask mandate, offering more predictability to businesses and residents.  They amended regulations to require seven consecutive days of “substantial” transmission in order to trigger a mask mandate. The council also decided that once 85% of of the county’s total population is vaccinated, the concept of mask mandates will permanently end and be taken off the table. The CDC website shows that 78% of the county’s total population is fully vaccinated.  Montgomery County’s website shows it as much lower at 69.7%, but the county’s data only reflects vaccination data for people who got their shot in Maryland.

To add another layer of complication, D.C. — Montgomery County’s neighbor — will be lifting its indoor mask mandate on Monday, Nov. 22. D.C. Mayor Muriel Bowser announced the change on Tuesday, as she and city health officials described a new era of mitigation strategies. Instead of treating COVID-19 as a pandemic, Bowser and DC Health director LaQuandra Nesbitt described it as an endemic disease, or one that constantly circulates at a baseline level in communities. With the mask mandate dropping, D.C. officials are vocally pivoting to an individual responsibility and risk assessment focus, and moving away from government-mandated precautions.

Still, D.C.’s case rate per 100,000 residents over the past seven days is 81, higher than that recorded in Montgomery County. The District also has a lower vaccination rate than its neighbor: city estimates show 63% of the total population is fully vaccinated, compared to Montgomery County’s 78%.

When asked about both localities moving in opposite directions on Tuesday, Bowser responded: “I don’t work for Montgomery County…I don’t actually know what they’re doing.” Prince George’s County currently has an indoor mask mandate, and has not announced plans to lift it.

Historically, Montgomery County has taken a more cautious approach to reopening during the pandemic, at times having some of the strictest restrictions on dining in the region, and standing at odds with Gov. Larry Hogan’s school reopening plans.