回复：Max =$17500 if age younger than 50

You may contribute up to $23,000 if you are 50 or older as long as the W-2 pay is over $23,000. Nothing to do with percentage.

If you company matches, try to make sure you can contribute every month so you don't miss the match.

For example, if you income is $120,000 and you make $3,000 contribution monthly and get match of 4%; by Nov, you can't contribute any more since your cumulative contribution is over $23,000; then your employer can't match you.