Several factors come into play when making the decision to take a lump sum pension payment, such as risk tolerance, life expectancy, how the lump sum would be invested, and whether or not the payments pass on to a spouse if you pass away before him or her.

Hopefully that's not a news flash to you, but it is for some people once they get to their 50s or so and start thinking about retirement. They might have had some idea that Social Security wouldn't cover everything, but they believed it would cover more than it actually does. (And, relatedly, they also might think Medicare covers 100% of their medical expenses once they get to Medicare age. Not true.

Retirement planning with a partner requires both of you to be on the same page. Make sure you have a retirement plan in place.

Some investors convert a traditional IRA to a Roth IRA without understanding whether or not they really should. Usually the best time to convert to a Roth IRA is after retiring but before Social Security and Required Minimum Distributions (RMDs) begin.

Accounting for long-term care is one of the trickiest parts of putting together a retirement plan. The uncertainty regarding long-term care is partly due to mispricing of long-term care insurance policies, which are a relatively new invention.