Also indicted on federal charges were two members of Siegelman's administration and Scrushy, the former head of the HealthSouth medical-services company who was acquitted earlier this year in a massive accounting-fraud case.
Siegelman, who was governor from 1999 to 2003, was charged with racketeering, fraud, bribery, extortion and obstruction of justice.
Siegelman called the long-running grand jury probe a political witch hunt by Republican prosecutors trying to derail his current Democratic campaign for a second term in 2006.
"I never put a dime in my pocket that didn't belong there," he said Wednesday.
The former governor was expected to turn himself in later this week.
The indictment alleges that Scrushy, former chief of the HealthSouth medical-services company, made disguised payments totaling $500,000 to Siegelman to get appointed to a key hospital regulatory board.
Siegelman's former chief of staff, Paul Hamrick, was charged with racketeering for taking bribes from a former lobbyist to steer state contracts to his business interests.
Former state Transportation Director Gary Mack Roberts was charged with fraud for his alleged role in influencing the agency on Siegelman's behalf.
Three other people with ties to the Siegelman administration have pleaded guilty to corruption in the alleged scheme — Nick Bailey, a former executive secretary and Cabinet head; Lanny Young, a former lobbyist and landfill developer; and Curtis Kirsch, a Montgomery architect who did work for the state during the Siegelman administration.
Wednesday's indictment alleged that Siegelman and Hamrick took hundreds of thousands of dollars in bribes from Young to aid Young's business interests, including awarding contracts to companies controlled by Young.
Young, Bailey and Kirsch had been scheduled for sentencing Oct 14 in Montgomery, but that hearing was postponed. No new date has been set.
As part of their plea-bargain agreements, the three men's sentences will be determined in part by their cooperation with federal authorities.
Scrushy was charged with bribery and fraud in an indictment filed May 17 but kept under seal, prosecutors said.
The indictment claims Scrushy made "two disguised payments" totaling $500,000 to Siegelman in exchange for Siegelman appointing him to the state's Certificate of Need Review Board, which decides on hospital expansions.
Earlier this year, Scrushy was acquitted in a criminal case stemming from a massive accounting fraud at the Birmingham-based HealthSouth chain.