The U.S. bond market is closed Monday in observance of Memorial Day.
The yield on the benchmark 10-year Treasury note rose slightly to around 1.851 percent, after spiking to 1.855 percent immediately after Yellen's speech. Meanwhile the yield on the 30-year Treasury note was about flat at 2.646 percent.
The was last up at 0.911 percent, after hitting a session high of 0.914 percent.
The U.S. GDP growth rate was revised to up 0.8 percent, as opposed to 0.5 percent as reported last month by the Commerce Department.
Consumer sentiment hit 94.7 in May, lower than economist expectations of 95.5, according to a consensus estimate from Thomson Reuters. The Treasury cash market closes at 2 p.m. ET.
In oil markets, Brent crude traded at around $49.33 a barrel, down 0.3 percent, while U.S. crude settled down 0.3 percent, or 15 cents, at $49.33 a barrel.
Major U.S. stock averages pared earlier gains on the back of Yellen's comments.