An example of a cap: the 50% match is capped at 6% of your salary so if your salary if $150,000 then they will only match that 50% on the first $9,000 of eligible contributions, so $4,500.

I actually think this is a terrible system as it punishes most the people who need it (ie lower level employees) but here we are.

For completeness, there is also vesting, which I mentioned. This means you get the match but if you leave within a certain period (eg 2 years) they will claim back your match.