WE NEED an army of workers to reopen the country. The good news is, a group of senators has an idea for where to find one.

Sens. Chris Van Hollen (D-Md.), Christopher A. Coons (D-Del.) and several colleagues introduced legislation this week to pay for 750,000 national service positions over the next three years. It’s a big number because it has to be: Experts estimate that the United States will require hundreds of thousands more public health employees to track cases, conduct tests and more. Contact tracing alone would call for almost 300,000 personnel to match the scale of successful efforts in Wuhan, China; more conservative estimates of what’s necessary still hover in the six-figure range.

The senators propose leveraging AmeriCorps and other existing programs to bridge the alarmingly wide gap between what the nation needs and what it has. Their concept makes good sense; these organizations already have partnerships with government agencies and the institutional know-how to perform all sorts of essential community-minded tasks. The bill would prioritize Peace Corps volunteers and Fulbright and other fellowship recipients, as well as, crucially, the many Americans this crisis has left unemployed. Another bill from Mr. Van Hollen and Sen. Edward J. Markey (D-Mass.) aims to mobilize FEMA volunteers with medical expertise to aid in roles that require it — but the bulk of the jobs crying out to be done are layman-friendly with minimal training.

The proposal offers an opportunity for national action at a time when President Trump has largely left states on their own. Localities are diverse and idiosyncratic enough that it can be easier for those on the ground to see what’s needed than for someone far away in Washington. But it’s abundantly clear that at the moment what’s needed, for everyone, is more. Standing up a ready-to-go cadre of Americans who can be deployed anywhere across the country would be instrumental in serving areas where staffing is relatively scarce and sickness is spreading — not only now but also in the many months ahead.

Studies say an additional $3.6 billion is required to enable governments to ramp up their tracing, and Congress ought to give it. The crisis is costing the nation that much in lost economic output every few hours. To begin to restore that output — to get people back to work — the country needs far more testing, and far more people to help implement a sound public health strategy. This legislation offers an essential building block for that strategy.

Read more: