The 73-year-old lawmaker faces 20 years in prison for taking payoffs from businesses trying to buy his influence.
The indictment doubles the amount Seminerio was accused of pocketing when he was busted on Sept. 10.
The feds say the veteran Democrat - who has spent three decades in the state Legislature - set up a bogus consulting firm called Marc Consultants to collect cash from businesses.
In return, Seminerio used his inside access to state lawmakers to try to win them favorable treatment in an eight-year scheme.
"That kind of relationship you can't buy for $1 million," Seminerio told a hospital official with business before the state, according to Manhattan federal prosecutors.
The unnamed businesses are described as a hospital, a consulting firm associated with an educational institution and a firm that markets supplemental insurance packages to public institutions.
The feds were alerted to Seminerio's scheme by disgraced labor leader and Queens pol Brian McLaughlin, who has already pleaded guilty to federal corruption charges involving $2.2 million in cash, luxury cars and other perks, the Daily News reported in September.
McLaughlin introduced Seminerio to an undercover FBI agent posing as a businessman, sources say. The agent paid Seminerio $25,000 to introduce him to several Albany lawmakers, prosecutors say.
Seminerio, a former correction officer, has represented southern Queens since 1978. He's accused of defrauding the public of his honest services.
His lawyer has said he was trying to work out a plea deal.