Why are investors leaving 401(k) money on the table?

When it comes to saving for retirement, too many people are not taking advantage of free money—and it's costing them, says certified financial planner Rich Coppa, managing director of Wealth Health.

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The rise of 401(k) plans has shifted the responsibility of saving for retirement to workers. Some aren't taking full advantage of employer-sponsored plans, and that means leaving money on the table. To that point, the Internal Revenue Service last month announced changes in the amounts you can contribute to your 401(k) plan.

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If you are younger than age 50, the maximum you can contribute from your paycheck is $18,000, up from $17,500.

If you are 50 years old or older, the IRS lets you contribute more, since you are closer to retirement. The maximum catch-up contribution has increased from $5,500 to $6,000. This means you could contribute up to $24,000 in your 401(k) for 2015 (base amount of $18,000, plus the $6,000 catch-up).

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Coppa says a good first step is for people to honestly audit their spending and decide on needs versus wants. Could you cut out some of your expenses and then apply the savings to your retirement account? Chances are that you probably can. Everyone should look at ways to cut expenses and start adding that to their regularly retirement contribution.

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Maxing out your retirement contributions is a good way to ensure you are building wealth for the future. Plus, it allows you to get the best bang for your buck. You end up with the potential for more earnings as your balance grows, and you also receive tax advantages.

—By Jim Pavia, Senior Editor at large