By everyone I mean random people who reach the site via Google, but they're common questions that I read or hear all the time so they make for a quick Q&A article. If you think any of my responses are off target, certainly give your opinion as well because I may very well be wrong!
The general consensus is that you should contribute enough into your 401k in order to earn the company match, if one is offered, otherwise maximize your Roth IRA contributions first. The logic behind this is that the Roth IRA is a powerful tool but not as powerful as free money (the match). This also has the added bonus of diversifying the tax burden of your retirement assets. So, get the match, max the Roth, then go back to the 401(k).
No! Actually, you can do whatever you want but considering that you can't put the money back into your IRA, I think it's a bad idea. Don't pilfer your retirement assets to pay off the debt, it may be better for you to pay off the debt in lieu of additional contributions or perhaps ratchet back your spending.
If you can afford to, the maximum. Save for the future! Actually, what you should do is put as much as you can afford to while maintaining a reasonable lifestyle. You don't want to max out your 401(k) at the cost of enjoying life now but you shouldn't be making weekend trips to Paris and ignoring your 401(k). If you want to make an error in either direction, then err on the side of caution and pump up the 401(k) now because time will be on your side. Waiting even five years to start contributing can result in a difference of tens of thousands when retirement comes around the corner.
They will generally match your contributions up to a percentage. At my former job, if you contributed 6% of your salary then the company would contribute 3%. If you contributed 10%, then they still would kick in only 3%. If you contributed 1%, they gave you 0.5%.
Anyone with income can open a Roth IRA and there are no rules for where the money has to come from. For example, if you had a summer job and earned $2,000 but blew it all on movies, diners, and dates then your parents can give you $2,000 to contribute to your Roth IRA. The only thing that matters is how much you earned. Also remember the contributions are after taxes so it's not your gross income, it's your take-home income that limits you.
Unfortunately no you cannot. The value of the Roth IRA contribution isn't your limiting factor. So if you contributed $4,000 and because the market tanked the Roth IRA is only worth $1,000, then you cannot contribute another $1,000.
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