What decisions can VAR review in MLS?

MLS plays under the IFAB Laws of the Game, and the VAR protocol (2026/27) lets a video assistant referee help the referee only for a "clear and obvious error" or "serious missed incident" in these match-changing situations:

• Goal or no goal: for example an attacking-team offence in the build-up (handball, foul, offside), the ball being out of play before the goal, or a goalkeeper/kicker offence at a penalty kick.
• Penalty or no penalty: including a penalty incorrectly awarded or not penalised, and whether an offence was inside or outside the penalty area.
• Red cards: denying an obvious goal-scoring opportunity, serious foul play, violent conduct, biting or spitting, or offensive, insulting or abusive actions.
• Mistaken identity: when the referee cautions or sends off the wrong player of the offending team. Only the identity can be reviewed.
• Incorrectly awarded corner kick: a competition option, only if it can be changed immediately without delaying the restart.

Source: https://www.theifab.com/laws/latest/video-assistant-referee-var-protocol/