401K Financial Planning

Jonathan asked:

If I buy 401k, is it possible to debut (put) 50% of my
monthly paycheck to 401k each month. I earn about $4,500 a month.

When I agree to buy 401k, does my monthly paycheck
get deduct for the next 12 month based on the percentage
taken out to equal the yearly maximum of $15,500?

or

Within 6 months, they will take out up to the maximum of $15,500 at a higher percentage to reach the maximum of $15,500/year?


Question posted courtesy of: Vanessa