Diagnosis
You're asking because you don't want to melt or crack the plastic. Yeah, this one's common.
How to Fix It
The clear Tritan pitcher, the lid, and the filler cap are all top-rack dishwasher safe. That's the official word from Oster. It's best to remove them right after the cycle to avoid heat warping from the dry cycle.
If That Didn't Work
The one part you must NEVER put in the dishwasher is the blade assembly unit (the metal part you screw onto the bottom). Dishwasher detergent and heat will corrode the bearing and ruin the seal. Always unscrew it and hand-wash it.
Heads Up
Even on the top rack, repeated dishwasher cycles can make the pitcher cloudy over time and may slightly degrade the printed measurement markings. Hand-washing is always gentler for longevity.