Most CEOs are anxiously counting the days until the coronavirus pandemic recedes, and employees can get back to the office. But Nationwide's CEO Kirt Walker has a slightly different take on working from home: It's working.

The company's pandemic experiment has gone so well that they've decided to make the arrangement permanent for many of the company's employees.

The shift took place fast—in early March, the privately held insurer (#75 on the 2019 Fortune 500) moved 98%+ of its 27,000 employees to working from home over five business days. "The first thing we wanted to do was keep our associates safe, stay connected to our members, and do our part for America to flatten the curve," says Walker.

But overall, once the tech issues were ironed out, there was a surprising finding: "We've tracked all of our key performance indicators, and there has been no change," says Walker, who joined as CEO in 2019. "We keep hearing from members, 'if you hadn't announced you were all working from home, we never would have known.'"

So Nationwide plans to shrink from 20 physical offices pre-crisis, to just four. Walker says he's splitting his own time between Nationwide's headquarters in Columbus, OH, and his home. He talked to Fortune by phone about what's driving this change, the future of work, and why Nationwide ends every day with a light show at its headquarters.

This conversation has been edited for length and clarity.

Were you prepared for this pandemic?

We’re an insurance company. Our focus is to manage risk. We’ve planned for a crisis for years. You cross out 'gas leak' and insert 'COVID,' but we knew for a long time we needed to be able to lift people out of the office and continue serving our members.

Did Nationwide previously have a robust WFH culture?

Pre-COVID, we had about 5,200 associates working from home already. And we've done a lot of sharing best practices, including one associate from Arizona who put together a manual that has been widely passed around. One of my favorite tips is that when you work from home, when you start your work day put your photo badge on, and when you end your work day take it off. Psychologically it allows you to start and end—and also lets your family know whether you are 'at work' or not.

Additionally, we had been working on a program called "The Future of Work" to explore transitioning more employees to working from home, it's something we hear especially from millennials that they want. So that was already in the works when COVID showed up.

Did you hit any roadblocks in those early weeks?

We decided early on that we were not going to let the perfect be the enemy of the good. It would take way too long. We just said 'we are going to make camp on the trail.' So one thing that came up is that for some associates, the headsets with microphones attached that worked with some systems in office didn’t work when people got home, so we had to scurry to get new ones delivered. And some associates didn't have adequate home internet, so our tech teams got involved to work with providers.

Why did you decide to make this change permanent?

At the end of the day, we looked at key historical events that shaped society: the Great Depression, the 1918 pandemics, WWI and WWII, 9/11, and the financial crisis. During these crises people reduced consumption, grew more frugal. After the crisis, worry continued and it was a permanent mindset shift. That’s really important. We think the world is changing. We’ve got to take cost out of the system. We want to enable sustainable growth.

How much money will this save Nationwide?

We are a private company, so we've decided not to share the numbers. But it will be substantial. The company and our members will benefit.

Talk a little bit about who is going to go back to those four remaining offices?

Candidly, there were those employees that were anxious about returning to work. So we decided to rely on volunteers to staff the first wave. About 25% of our workforce said 'I want to come back.' We won’t ask or force those that don't want to. We believe we'll end up in a hybrid model: Employees will have access to a 'hotel' in the office were they can come in and collaborate, maybe a day or two a week, then other days they'll work from home.

Some bosses get extremely nervous when they can’t physically see their employees. How do you avoid that?

We hire for attitude. We have built a culture where we can trust associates. And they are using the same technology now that they had in the office. We rely on 10 key performance indicators, and employees can monitor their own work day to day, and so can their supervisors. We don’t try to hold people accountable with amount of time they're putting in, but rather how well they are doing on those indicators.

How has your overall business changed during coronavirus?

Applications have decreased as people have hunkered down. But we have also seen a decrease in the number of claims. We heard from a lot of members saying 'I’m having a really tough time financially.' So we decided to send rebates of $50 to all personal policy holders. The feedback we got was, 'I was really needing a couple of bucks.'

As we look ahead though, we are thinking about all these patterns that develop during a crisis and how behavior will change. We think that in many lines of insurance people will be looking toward value-based products, while on the financial side of the house people will look more towards guarantees. Especially millennials may be thinking, they aren't sure about betting on equities or relying on an employer. They need to provide for their own retirement.

Are YOU going to be working from home? How does your family feel about this?

I bounce between the two. There were days that I forced myself to work from home. I wanted to empathize with my associates about what working from home was really like. I have an empty nest now, but my wife and I go over our schedules every day together. You have to communicate. One thing I love to see is that for weeks now, at our main headquarters building in Columbus, every night we light up the office windows to spell out "Stay Safe." It's a sign to everyone that we'll get through this together.