Four small retirement planning mistakes that'll cost you

Small mistakes can have a big impact on a retiree's financial security; SmartMoney magazine calls these four glitches the most costly errors:

  • Underestimating healthcare costs

  • Giving too much money to family

  • Investing too conservatively

  • Failing to make a plan for all that free time

While those are all problems to avoid, I think there are some others that can leave a retiree high and dry if he doesn't pay attention. Here's my list of four items: