回複：401k is non tax deductible,

if you enroll 401k with your company you can put max $14000 or 50% of your salary; the amount is pre-tax, which means the amount will not count as your gross income you don't need to pay tax for it. if your total income is in high rate this might be a way to lower your tax. you need to pay tax when you at 65 yrs old(401k early withdraw will have penalties) and mostly that time your tax will be lower than now.

you can borrow against your 401k account, but need to pay back with interest to the account and if for some reasons you leave the company you need to pay back the full amount. my friend took some amount out of his 401k for their first residential house and he didn't need to pay back, so check with your company