Its that time again. Soon youll receive an important form in the mail from the U.S. Census Bureau, and workers may even knock at your door to ask questions about the people who live in your home. Depending on your age, you may have never experienced this as a respondent before, as a nationwide census happens only once every 10 years.

So as we prepare for the 2020 census , you might be wondering what the process actually entails. Below are answers to some of the biggest questions surrounding the census and how it works.

Why do we have a census, anyway?

The census is conducted every 10 years for a few important reasons. For one, its required by the Constitution. The sixth sentence in the constitution specifies that there will be a census every 10 years in the United States, counting everybody who lives here, explained Jonathan Williams, an applied data science manager at Civis Analytics .

But why is it so important?

Census results are how we apportion congressional representatives from each of the states, Williams said. Its also how we disperse about $1.5 trillion of federal funding per year. For example, the data will dictate where new schools are needed, where new roads and bridges should be built and how funds should be dispersed among programs such as Medicaid and the Supplemental Nutrition Assistance Program (formerly known as food stamps).

Census numbers also inform statewide redistricting efforts (how legislative districts are drawn and along which lines).

Theres also a significant research component not only academic research, but consumer or commercial research. Decisions such as where to situate new stores or which ads to run are based, in part, on census research, according to Williams.

What does the census process entail?

There are a few different phases to the census, the first of which is a self-response period.

Starting in March, you should receive a postcard from the U.S. Census Bureau that includes instructions for how to participate. According to Williams, this is the first time that the census will include the option to participate online , which 6 in 10 households that fill out their own report are expected to do.

However, those who have limited internet access or are concerned about security risks or scams can complete their census forms on paper and mail them in, or answer census questions over the phone.

April 1 is considered the official census day, but almost all households should have received their census form in the mail by then, Williams said. After about a month of that self-response period, the Census Bureau will begin whats called a nonresponse followup, he added.

This is the step in the process that a lot of people tend to associate with the census. If you do not fill out a form, census takers will collect your information through an in-person interview by going to your door. Theyll come around several times in case youre not home, Williams said.

If youre not home when a census taker (known as an enumerator) comes around, or you refuse to participate in the in-person interview, they may then resort to backup methods, including proxies. They may ask a neighbor or a landlord about some of the information they might know about your household, Williams said. As the very last resort, theyll use a method known as imputation, where they use a combination of administrative records and statistical likelihoods based on where you live to fill in the data gaps.

Keep in mind that this whole process may be changed as we learn more about the coronavirus situation more on that below.

How do you know if a person at your door is a real census taker?

Though you can expect someone to come knocking on your door this summer, always use caution when answering. Census enumerators will always have an ID badge with their photo, which includes a U.S. Department of Commerce watermark.

Additionally, they will only ask questions that are on the census form. You should never be asked about your Social Security number, immigration status, financial information such as bank account or credit card numbers, or for donations. Census takers will also never enter your home.

When in doubt, call your local Census Bureau representative to verify the persons identity. A legitimate representative should have that contact information on hand and will present it if asked.

Whats the planned 2020 census timeline?

Below is a brief overview of the important dates related to the 2020 census:

January 21: The census got a head start and began counting the population in remote Alaska.

March 1220: Your household should receive an official piece of mail from the U.S. Census Bureau with instructions on how to respond to the 2020 census by web, phone or mail.

March 30April 1 (postponed): These were the planned dates for the Census Bureau to attempt counting people in homeless shelters, tent encampments, on the streets and others currently experiencing homelessness. However, due to concerns over the coronavirus, the Census Bureau is suspending all field operations through April 1.

April 1: This is the official census day when every household receives an official invitation to participate in the 2020 census.

Throughout April: Census workers will begin counting people who live in large groups, such as college students who live on campus and seniors who live in group homes. They will also conduct quality check interviews to make sure the count is accurate.

MayJuly: This is when census representatives start the process of in-person interviews for households that havent responded yet.

December: Apportionment counts are provided to the president and Congress.

March 31, 2021: The Census Bureau will have sent redistricting counts to states by this date.

What happens if youre not counted in the census?

All the methods of nonresponse follow-up outlined above are more likely to introduce mistakes into some of the details about households. So its incredibly important to respond to the census.

One consequence of missing or incorrect census data is that the total population count becomes less accurate. And thats a big deal because it directly affects both federal representation and funding. When you have inaccurate lower totals counted in some states, both apportionments in Congress and federal funding are not divvied up as they should be, and representation and funds end up going to other states instead.

Williams added that theres an equity component to this as well, because the people who end up not being counted in the census arent missed at random. Specific populations such as young children under five years of age, renters, minorities and non-citizens are examples of groups that historically, have not been as well counted by the census as other groups, Williams said.

And if those populations, in particular, arent counted relative to others, it could skew whether programs that make funds available for specific communities actually end up receiving the correct amount of funding.

If you somehow missed your opportunity to self-report using the official census link or paper form and didnt talk to a census worker in person, dont worry. You can still participate in the census, even months later. Simply go online to the Census Bureau website and respond online using their secure form.

Will there be a question about citizenship on the 2020 census?

The census is intended to count every person living in the U.S., whether a citizen, noncitizen legal resident or otherwise. Over the last couple of years, the Trump administration had been pushing to add a question to the census form asking whether respondents are U.S. citizens. Critics of this change worried that it would lead to low response rates among noncitizens and Latinos, leading to unfair political representation (which some believe was the administrations goal).

Ultimately, the Supreme Court blocked that proposal last June, stating that there was insufficient reasoning for why that question should be added. So rest assured there will be no citizenship question in the 2020 census.

How is the census being handled in light of the coronavirus?

One potential challenge for the 2020 census is how workers will conduct in-person interviews as the coronavirus continues to spread. People may be less likely to open their doors to strangers. And census workers will be at risk of contracting and spreading the disease due to the high level of in-person contact required.

Until recently, there was no official plan in place to change how the census is conducted, and several senators called for the Census Bureau to address this concern. On March 18, the bureau announced that it would suspend all field operations for two weeks through April 1. During this pause in field operations, the Census Bureau will continue to evaluate all 2020 Census operations. Should any additional adjustments need to be made, the Census Bureau will communicate these changes broadly and promptly, it stated.

For all other surveys conducted by the Census Bureau that are separate from the 2020 census, personnel will rely on phone calls instead of in-person visits.

One final note: Watch out for census scams.

Getting an accurate count in the census is incredibly important, as it ensures that political representation and federal funding are doled out appropriately. Unfortunately, some people view this time as an opportunity to skew results or scam potential census participants.

For example, last month, Republicans mailed out documents titled 2020 Congressional District Census, in envelopes labeled Do not destroy, official document. The lengthy forms were printed with colors and fonts that mirror the official census but were not actually related to the census at all. It was a clear attempt to confuse people and cause inaccurate counts. Heres how you can verify if a mailing is real .

Other census scams tend to pop up around this time as well. Be wary of ads on social media or phishing emails encouraging you to follow the link and fill out the census form online; these emails are not from the Census Bureau and contain malware that can steal your personal information. Also, the Census Bureau will never call you and ask for money or personal information such as your Social Security number. If you receive a phone call from someone claiming to be from the Census Bureau and arent sure if its legitimate, heres how to verify its real .

This article has been updated to reflect the Census Bureaus March 18 announcement that it was suspending field operations until April 1.