The 11-year veteran will miss Sunday's game against San Diego, which will cost him one game check of more than $400,000.
Reed is suspended for three violations of the player safety rules in the past three seasons. The latest came in Sunday night's 13-10 victory over Pittsburgh when he was penalized for unnecessary roughness in the third quarter for a hit to the head of receiver Emmanuel Sanders.
Reed also was penalized Sept. 23 against the Patriots for unnecessary roughness and fined $21,000 for striking Deion Branch when the receiver was defenceless.
Before that, Reed hit Saints quarterback Drew Brees on Dec. 19, 2010, and was fined $10,000.
"We cannot tolerate repeated violations of rules, especially rules related to player safety," NFL executive vice-president of football operations Ray Anderson said Monday. "We will continue to take the strongest possible action to deter these types of violations and protect our players."
Steelers safety Ryan Clark tweeted: "Tough on Ed getting suspended. I can't say that I agree w that. It was a penalty but I don't believe he was intentionally trying to harm E."
Under the collective bargaining agreement with the players' union, the suspension can be appealed within three days. An expedited hearing and decision would take place this week.
Appeals are heard by either Art Shell or Ted Cottrell, the officers jointly appointed by the NFL and NFL Players Association.
Ravens coach John Harbaugh disagreed with the league's ruling, saying: "I was very surprised, I didn't see that one coming."
"They were all inadvertent," Harbaugh said of the three hits cited by the NFL. "None of those were with the intent to injure or to harm in any way. I think when you look at the hits it's pretty obvious. When you look at Ed, he respects the game, he respects the players."
Reed is the second player suspended this season for violating rules designed to protect players. Denver linebacker Joe Mays was barred for one game for an illegal hit against Houston quarterback Matt Schaub on Sept. 23.
Others suspended for similar hits in past seasons include Steelers linebacker James Harrison and Lions defensive tackle Ndamukong Suh in 2011; Panthers defensive back Dante Wesley in 2009; Tampa Bay DB Elbert Mack and New York Jets safety Eric Smith in 2008; and Cowboys safety Roy Williams in 2007; and Titans DT Albert Haynesworth in 2006.
Online: http://pro32.ap.org/poll and http://twitter.com/AP_NFL