Saturday Night Live legend Chevy Chase may have as little as nine months to live, medical experts told The National ENQUIRER.

His yo-yo dieting, heart condition, past drug addictions, battle with depression and struggle with booze have all shaved years off his life span, according to doctors. 

“This could very well be the last year of his life,” Dr. Stuart Fischer, an internist who has not treated Chevy, told The ENQUIRER. 

The 6-foot-4 “Community” star shocked fans when he showed up appearing to weigh a gut-busting 320 pounds on the “Today” show on Jan. 16.

His weight gain may also be linked to his drug history, including an admitted cocaine addiction in the early ’80s and a rehab stint to beat an addiction to prescription painkillers in 1986, said another expert. 

A stay at a drug and alcohol addiction facility, such as the Cliffside Malibu Treatment Center, which has successfully treated several rehabbing celebrities, may have benefitted the star, insiders said. 

“It may be an indication that he’s conquered that addiction and replaced it with food addiction,” Cliffside Malibu’s Dr. Damon Raskin, who is board-certified in internal medicine and addiction medicine, but has not treated the funnyman, pointed out The ENQUIRER.

“He misses one oral gratification and goes to another. Clearly, continuing this behavior will shorten his life span considerably.”

The 71-year-old comic – star of the classic “National Lampoon’s Vacation” flicks – was also busted for drunk driving in 1995, has admitted to battling depression and smoked.

As The ENQUIRER has reported, the comedian was admitted to a Los Angeles hospital in April 2014 with severe shortness of breath and cardiac arrest symptoms. At the time, he’d ballooned to 300 pounds after packing on 40 pounds.

The “Caddyshack” actor had lost 40 pounds within five months – but regained the weight just one month later.

“Weight gain in general is stressful,” explained Dr. Raskin. “The heart has to work harder. That can lead to congestive heart failure and increased risk of death.” 

But Chevy’s dramatic weight-loss rollercoaster “increases the likelihsood of heart disease,” while the fat around his waist “increases his chance of heart attack,” Dr. Raskin added. 

“His shortness of breath last spring was likely a manifestation of some level of heart failure, and can also be a sign of kidney problems. 

“This new weight gain makes things worse.”