The fund is intended to help people who became ill after working at ground zero and others whose sicknesses can be tied to the site. Residents, workers and others can apply, including those whose claims to the first fund were denied.
"Everybody who is eligible should apply for this," said John Feal, a leading advocate for injured first responders.
The deadline for applying for help is Oct. 3, 2013, or two years from the time a person learns that a physical injury or sickness resulted from exposure to ground zero. The program will run for six years.
Congress established the fund after the 9/11 terrorist attacks. It operated for two years, giving $6 billion to victims' families and $1 billion to the injured. Last year, Congress passed the James Zadroga 9/11 Health and Compensation Act to reopen the fund and provide additional help to people affected by the disaster and its aftermath.
The new federal law allocated $2.8 billion for compensation and $1.5 billion for medical monitoring and care.
Many illnesses common among people exposed to the site are presumed covered by the fund, such as lung disease and chronic sinusitis. But it won't cover cancer, despite the protests of first responders who have been diagnosed with the disease and believe it's linked to their time clearing smoldering debris from the site.
Federal officials say too little scientific evidence exists linking cancer to exposure to ground zero. Next year, officials plan to review which illnesses should be covered.
Applicants have to show evidence of their diagnosis and time spent at the site. If an illness is added to the program, people suffering from that illness will be permitted more time to apply.
The new fund also covers a bigger geographical area in New York City. The eligible zone includes all of lower Manhattan south of Canal Street. The period a person could have been exposed to the site also has been extended - to May 30, 2002, more than eight months after the attacks.
Special Master Sheila Birnbaum, who was appointed fund administrator by U.S. Attorney Eric Holder and who is working pro bono, has promised to process claims as quickly as possible.
Still, cleanup worker Martin Davin, 54, of Jersey City, N.J., said he feared help could come too late. He cleaned dust from buildings around ground zero and was diagnosed with lung disease two years ago.
"They concentrated more on building the memorial to people who are already dead than on taking care of people who are still trying to survive," Davin said. "I've been hospitalized six times. One day I'm probably just not going to go home."
Feal said he spoke with Birnbaum on Friday and felt confident she would handle the claims fairly.