It’s tough enough to save for retirement without having to sweat over hidden fees in your 401(k). But if you are overlooking a “leak” in your pension plan, it can dribble away thousands of the dollars you’ll be depending on for a comfortable retirement.

That leak comes from fees that can be levied on your account year after year, writes money columnist Albert Crenshaw for AARP magazine, for everything from money management to record keeping.

Pay close attention to your retirement account. While most employers do a good job of insuring that their 401(k) plans are free of unnecessary fees, make sure your choices are no-load mutual funds, meaning they don’t cost you a percentage to get into and get out of.

Hidden fees should be spelled out in each fund’s prospectus, but you can look online at Morningstar.com or Yahoo.com if you know the ticker symbol of the fund (a five letter combination, usually ending with “X”).

In particular, look for the lines labeled “expense ratio,” “front-end sales load,” “back-end sales load,” and “12b-1 fee.” There’s no need to pay any of the loads, but the expense ratio is necessary.