You want to identify if you have a traditional plan (before tax) or a Roth plan (after tax). You should consider a Roth plan, if you are not making that much money and you expect to pay more taxes later — $60,000 is a rough number to use when deciding. Under $60,000, go with the Roth; over $60,000, go with the traditional. This is not a hard science; make the call after plenty of consideration, when taking into account your own particular situation and the federal and state income taxes you pay. Take your time, and educate yourself about your options before you act.
This issue gets a bit more complicated when you live in a no income tax state. You might want to increase that $60,000 number to $80,000 when determining whether to go Roth or Traditional. As for the married folks, $120,000 in total family income could be used as a threshold. Under that amount go with the Roth and over that number, go with the Traditional. What if you live in a no state income tax state? You might want to increase that amount to $160,000 or something close to that amount. If you are close, you could also do some Roth and some Traditional. Make the call!