Moyer has been sober for 14 years and has worked with CLARE for more than five years, according to the Hollywood Reporter.
He told the magazine that he wanted to work with the non-profit organization because it's one that people don't need a big bankroll to get help from.
Moyer, 45, who is married to his former co-star, Anna Paquin, said he's never spoken about his past addiction but that everyone in his immediate orbit already knows.
"As my wife said this morning, there isn't a restaurant in Venice or Santa Monica where I would be offered the wine menu," Moyer said during the panel this past Friday. "The Diet Coke, which is the patron saint of drinks for alcoholics, gets put before me before anyone even asks what we're drinking."
Moyer said his troubles with alcohol came from his roots in British theater and emulating the public images of his heroes such as Peter O'Toole and other reported heavy drinkers.
"There's this rush that happens from doing our job, this whirring buzz, and you want to continue that buzz," explaining why he developed the problem that caused him to enter rehab in England 14 years ago.
"Self-loathing motivates the desire to get loaded in the first place -- and post-sobriety, there is the shame of admitting all of your [faults]," he added. "It's about education. And it's about getting rid of that shame."
The premise behind the panel was to focus on success stories, not just the tragedies that are portrayed so often in media.