<prompt> Human: I just got a new job a few weeks ago. I am in the position to save most of my paycheck due to very low living expenses. My company offers a 401k match as a percentage of salary. I want to max out my 401k for this year. Would the match be based on my total salary, or the amount I made for this year August to December? If I contribute the max to my 401k, the remainder that I earn will be less than the standard deduction. Does this mean I will owe no federal income taxes? If so, can I stop federal income tax withholding? How would I go about that? Now more of a personal question: I am living in my mothers house rent free. I take care of the yard, dogs, etc. so she can live with her boyfriend, it is mutually beneficial. But now that I am able to pay rent, I feel an obligation to contribute. But she isnt great with money and will probably spend the extra income on frivolous things. Id rather the money go toward the house, or into savings. How would you approach this situation? Finally: Anyone ever regret saving too much money? I am in the position of saving the vast majority of my pay check. This would set me up pretty well for the future. But is there anyone who looks back and wishes they had lived a little and enjoyed life more instead of living well below their means?Edit: Thanks for all the help. Good info in this thread.  <response>: If you earn less than the standard deduction after subtracting your 401k contributions, then yes, you wont owe federal income tax. Note that on top of the standard deduction, theres also a personal exemption unless youre claimed as a dependent, in which case that person gets the personal exemption. In general you can make about 10000 without paying any federal income taxes.Regarding saving, saving more is usually good, since then you can retire earlier. That said, dont be stingy; for instance, I splurge on stuff I care about, like having a decent computer to play computer games. 