In 2000, about 200,000 New Yorkers did not fill out their census forms, and it cost the state more than $3.5 billion in federal funding.
Right now, the city says the numbers aren't even close to what they should be.
From Jerome Avenue in the Bronx to Jackson Heights in Queens, time is of the essence for community activists and census workers.
"There are some parts of the city where only 17 percent of the households have completed the census -- 16 to 17 percent, that's pretty bad," said Commissioner Fatima Shama, of the Mayor's Office of Immigrant Affairs.
And the problem is the worst in the immigrant communities, but only some people realize how important it is to fill out.
Queens resident Isabel Mayorga says she wants to be counted. She believes it's good for the community, schools, libraries and everything. But others in the community may struggle with fear, language barriers, or confusion.
During the last census in Queens, the federal government actually stopped immigraiton raids. But that's not the case this time around, which is why there is still some concern in the community.
"So they're afraid if they have a Muslim sounding name, that they will be rounded up somehow. So we are really trying to work hard to dispell those fears," South Asian Community Advocate Afreen Alam said.
Some of the immigrant communites wonder: If the census doesn't ask for immigration status or Social Security numbers and information is not shared with Homeland Security, what is the purpose of filling it out?
Officials say it is crucial for certain groups who may deserve greater representation, and they are urging everyone to complete the forms by April 15th.
Need Help with Filling out your 2010 Census?
Call: 1-866-872-6868 (Help in English), 1-866-928-2010 (Help in Spanish)
Phone lines are open nationwide from 8 a.m. to 9 p.m. (local time), seven days a week, through July 30, 2010. Deaf and hard-of-hearing persons call the TDD number: 1-866-783-2010
The Census Bureau posts daily "participation rates" on its 2010census.gov Web site for every state, county, city, town, township, Indian reservation and neighborhood. It partnered with Google to provide the interactive maps, which will be updated every Monday through Friday.