Getting paid less than coworkers at same level

If you really, really want to bring it up, I would set a meeting with your boss and just say that you were hoping to set up a feedback session, and would love to understand any constructive feedback that you could improve on. In that meeting I would say that you are aware that most of your peers (if that’s true) were awarded a higher all in compensation, so you’d like to understand what you can do to set yourself up for success during this year. I wouldn’t ask them to adjust your compensation - either it was a mistake and they may offer, or it was intentional and you’ll look foolish for getting bent out of shape over such a small difference. It’s better to slip it in, in the context of aiming for a path toward future improvement.

The more important question, however, is whether everyone other than you got the same thing, or if there is a spread of buckets. If it is a spread of buckets, I would really urge you not to bring the compensation piece up at all. If it seems like compensation was broadly lockstep and you are literally the sole exception, then you could potentially do what I suggested above.

Edited to add: One other point that seems to get missed sometimes by associates (which may or may not be the case here) - there is a difference between not having negative feedback and being a top performer. Sometimes, people are simply meeting expectations, or not doing anything "wrong" per se but just aren't performing at the same level as their peers. That usually manifests itself as feedback to "continue working on attention to detail" or "continue to expand your understanding of the bigger picture" or other such generalities. In fairness, that's partially a failure of management to deliver useful feedback, but you'll be surprised how hard it is once you get there and are dealing with a perfectly fine, average performer. One thing you could do, if you think that you're not viewed as a top performer but aren't getting actionable reasons, is to ask someone you work with directly, make it clear that you won't be insulted or take it the wrong way, and then ask for specific examples about what top performing associates do that you are not doing. If it is someone that knows you won't be resentful and you have a good relationship with, then hopefully you can get them to do a compare / contrast with the top bucket associate so you can actually figure out what you're not doing (even if you're doing all the basics). Again, it usually ends up being more trustworthy work (for example, maybe your materials need two iterations which is fine, but another associate literally delivers product that requires no comments because they thought through the messaging better), better understanding of the big picture (kind of the same idea), more proactivity (i.e., you do what you're asked in a timely fashion, but another associate totally anticipates what will need to be done and can basically be put on autopilot), etc... People usually hesitate to give that feedback if you're doing fine because it's sort of "nice to have" but those are typically the sort of thing that actually set people apart (and it's probably useful to understand that regardless of whether this 5% lower bonus was intentional or not).