Harbaugh was signed to a 4 year contract last year after winning the Ravens' second Super Bowl. Last night Bisciotti awarded Harbaugh a 1 year extension, signing him through the 2017 season.
The extension is clearly a public show of support during an offseason in which the media and fans have openly questioned Harbaugh's personnel and in-game decisions following an 8-8 season. 2013 marked the first season in Harbaugh's tenure that he has not taken the team to the playoffs. Even still, Harbaugh's record as a coach is 71-38 in 6 seasons giving him the 4th highest active winning percentage at .651.
Bisciotti told Jeff Zrebiec of the Baltimore Sun:
The only gesture I could make to John after us not making the playoffs was to extend him and I did when we were in Florida
... When we were down in Florida [for organizational meetings], I just told him, 'I just want you to know that I think just as highly of you after this disappointment,' so I added a year on his contract so he’s back to a four-year deal.
The Ravens are definitely trying to make a push to lock up their staff for the future and let everyone know that a single disappointing season isn't enough to start a new coaching search. After an offseason full of new coaching hires for the team, I can't say that I blame them.