By Thanksgiving, if all goes according to plan, every family known to be living on the streets of Orleans or Jefferson parishes should be housed.

Within three years, advocates should be able to house every homeless person who is disabled or younger than 25. And by 2020, the two parishes’ homeless populations should be slashed by 75 percent.

However, those ambitious goals — announced by leaders of UNITY of Greater New Orleans at its 24th annual meeting Monday — will be achieved only if the nonprofit organization and its partners find the money and manpower to accomplish them.

It’s not the first time UNITY’s leaders have made such bold predictions. The group’s executive director, Martha Kegel, told advocates two years ago that New Orleans was on track to stamp out chronic homelessness by Aug. 29, 2015, the 10th anniversary of Hurricane Katrina.

As it happened, the city did not end chronic homelessness by that date. But officials say New Orleans did bring its homeless veteran population to what President Barack Obama’s administration calls “functional zero” — meaning that officials have a process and the resources to house a veteran within a month after finding that individual on the streets.

UNITY now wants to apply that standard to other homeless populations in Orleans and Jefferson parishes, officials said.

“Homelessness will never go away, but when you hit functional zero, that’s an amazing standard,” said William Hines, outgoing chairman of UNITY’s board.

The new plan was finalized after numerous meetings with UNITY’s partners, Kegel said. To get the populations of homeless families and young adults to functional zero by this Thanksgiving and December 2019, respectively, officials plan to improve their data collection for those groups, hire staff to ensure those individuals are connected to available housing programs, and lobby state and local lawmakers to work to increase affordable housing opportunities.

They also will seek to reunify children and young adults with their families and will consider creating programs tailored to lesbian, gay, bisexual and transgender teenagers and young adults, who officials said are more likely to be unable to return home once separated from their families.

In addition, officials plan to ask the Housing Authority of New Orleans and the Jefferson Parish Housing Authority to beef up programs that provide rental assistance to homeless families.

To try to end chronic homelessness for people with mental disabilities and physical illnesses by July 4, 2017, UNITY will work to expand what is called permanent supportive housing, meaning affordable apartments with access to case workers who help get the occupants to physicians, substance-abuse counselors and other help.

And to try to slash all street homelessness by 75 percent by 2020, the organization is counting on a new federal grant to provide additional permanent supportive housing, plus the city’s planned low-barrier homeless shelter.

The federal grant dollars UNITY is seeking must be matched by either local money or volunteer time, officials said. That means the organization likely will be turning to local philanthropies to help fill gaps over the next four years.

The hope is for more success stories like that of Arthur Sylvester Jr. — who was homeless for more than a year but received his apartment Monday — and Brandy Haley, a mother of four who finally received a voucher for a long-term home for her family after bouncing from shelter to shelter since she lost her job, she said.

“What do I see, out of all of this here?” Haley said, referring to the time she spent on the street.

“I see that there is a brighter day.”

The crowd applauded.

Follow Jessica Williams on Twitter, @jwilliamsNOLA.