Beginning Thursday, millions of Americans will receive notices inviting them to complete the 2020 Census. Some will also get a paper questionnaire, but for the first time ever, most Americans will be encouraged to reply online or by phone. For those who don't respond, in-person visits from Census workers will begin on May 13.

"If you fill the Census out in the first four to five weeks online or by phone, you can avoid the door-knocking,” said Julie Menin, director of NYC Census 2020. “And that's the number one message we really want New Yorkers to know.”

"The Census doesn't involve calling people to a mass meeting,” Mayor de Blasio said Wednesday. “It's really about going out into communities and connecting with people briefly, one-on-one, making sure that they've followed through."

For that reason, coronavirus is not expected to cause a massive disruption to the census. Still, some informational forums have already been canceled. And there are concerns about hiring and retaining outreach workers wary of door-to-door contact with strangers.

Census officials on Wednesday suggested in-person visits could be canceled in areas where there's an outbreak, saying in a statement: "If we need to delay or discontinue nonresponse follow-up visits in a particular community, we will adapt our operation to ensure we get a complete and accurate count."

And, noting a significant contingency budget, officials added: "As needed, we will hire additional workers, manage operations out of different offices or mail additional reminders or questionnaires to areas affected by an outbreak."

The city's own outreach effort, with $40 million in funding, continues unimpeded.

"We're really using technology to our advantage in this situation. We're doing text-a-thons, we're doing phone-banking,” Menin said. “We can reach hundreds and thousands of New Yorkers."

And the Mayor says he's seen no sign the Census could be delayed.

"It's something we should study to see if there is an argument for the federal government to do that in this environment -- whether we're going to get an aberrant census and the dangers that could come with that,” he said. “But until that decision is made and formal, we have to assume it's on and we have to continue our effort."