Proposed changes to the World Trade Center Health Program have Sept. 11 first responders worried about their future health care as Ground Zero-related complications continue to affect them.

President Donald Trump's 2019 budget proposal would push the program to a new agency. It covers about 83,000 people who responded to the terror attacks that day.

One of them is Westbury's Mike O'Connell, who was a 25-year-old FDNY firefighter on the day of the attacks. Five years later, he says he developed a rare joint disease.

"There are days where my joints are enflamed so bad that I can't even get out of bed," he says. 

Critics warn the change could disrupt lifesaving medication and surgical treatment for first responders.

Rep. Peter King says the proposal directly contradicts a congressional vote three years ago to renew the World Trade Center Health Program for 75 years. 

"There's probably never been a federal program that has gone through with no complaints, no criticisms, no allegations of mismanagement," King says. "This has been an entirely 100 percent effective program."

Comedian and activist Jon Stewart described the proposal as "a special kind of incompetence."

"Why mess with something that's already working?" O'Connell asks.