If you're contributing money to a retirement account regularly, you're doing better than many Americans. Approximately 15% have no retirement savings at all, according to a study put out in May by Northwestern Mutual.

But just having a retirement account isn't enough to ensure you'll have what you need when you exit the workforce. You also need a clear, well-thought-out plan so you don't accidentally sabotage yourself. It's a more common issue than you think and not all the hurdles are obvious.

Here are three ways you may unknowingly be putting your retirement security at risk.

Mature man at laptop looking frustrated

Image source: Getty Images.

1. You don't have an actual retirement plan

Putting aside a chunk of your savings each month is not a real retirement plan. A retirement plan helps you estimate how much money you'll need to cover your living expenses for the rest of your life. Without one, you could come up short. You'll never get it exactly right because there are too many variables, but you can come up with an educated guess.

Start by estimating how long you'll live, erring on the high side. You could live past 90 or even 95 if you're in good health. Subtract the age you plan to retire at to calculate your estimated retirement length. Be prepared to adjust this if need be as an extended illness, layoff, or forced buyout could mean you work longer than planned.

Next, total up your estimated monthly living expenses, including any home or auto payments, utilities, insurance, and groceries. Multiply these costs by 12 to get your annual living costs, then multiply that figure by the number of years of your retirement, adding 3% per year for inflation. Your retirement calculator should do this part for you. Then, add in any travel expenses or big-ticket items you hope to purchase in retirement. You'll also have to estimate your investment rate of return. Use 5% to 6% to be conservative, though your investments may grow more quickly.

Finally, you must figure out how much you need to save on your own by subtracting the money you'll get from other sources like a pension, Social Security, or an employer 401(k) match. If you're not sure what to expect from Social Security, create a my Social Security account and use its estimates as your baseline. Subtract this from your total retirement expenses to find out how much you need to save personally. Your retirement calculator should also tell you how much you need to save per month to hit your goal.

Try to save at least this much, but stay mindful of contribution limits. You may only contribute $6,000 to an IRA in 2019 or $19,000 to a 401(k). Anyone 50 or older may contribute an extra $1,000 and $6,000 yearly in catch-up contributions, respectively.

2. You're paying too much in fees

Every retirement account charges fees, though you may not realize it because the money comes out of your account automatically. How much you'll pay depends on your account type and what investments you have. There are administrative fees, which cover the costs of record keeping and special services like account rollovers. Be aware that smaller companies may have 401(k) plans with higher administrative costs than larger companies because there are fewer employees to share in the plan's cost of administration.

There are also fees associated with your investments unrelated to the company you work for. Mutual funds and exchange-traded funds (ETFs) charge expense ratios -- an annual fee -- to all shareholders. This is a percentage of your assets, and you can find it listed in the investment prospectus.

If you are planning well, you shouldn't pay more than 1% of your assets in fees each year. On a $1 million portfolio, that amounts to $10,000 per year. If you're paying more than this, see if you can move your money to lower-cost investment products, like index funds. These are mutual funds that passively track a market index, like the S&P 500. That may not be an option in your 401(k) if your employer only offers a limited choice of investments. In that case, if the company's not matching any of your contributions, you may be better off moving your savings to an IRA. These accounts usually have lower fees and a greater variety of investments to choose from.

3. You withdraw money from your retirement account before age 59 1/2

Typically, you can't withdraw from your retirement accounts before age 59 1/2 without paying a 10% early withdrawal penalty as well as any income tax if the money came from a tax-deferred account. But there are exceptions to this rule.

You can choose to take substantially equal periodic payments (SEPPs). Or you can withdraw a certain amount of money penalty-free for a first-home purchase, qualifying educational expenses, or for medical expenses that exceed 10% of your adjusted gross income -- income minus tax deductions. If you have a 401(k) plan, you can also arrange to take out a loan that you must pay back within a set time.

But just because you can take out some of your funds penalty-free doesn't mean you should. Even if you only take out a 401(k) loan that you intend to pay back with interest, the consequences can be far-reaching.

Imagine you borrow $10,000 from your 401(k) to cover an unexpected expense. You arrange for a 10-year loan term and the plan charges an interest rate of 6.5%. Over the loan term, you'd pay back the original $10,000, plus another $3,626 in interest, putting $13,626 back into your retirement account. But if you had left the money in your account instead of taking out the loan, and it was earning the historical average market return of 7% annually, you would have $14,069 in your account after 10 years. That's an extra $443. If there's a larger spread between your loan interest rate and the actual rate of return during the loan term, the difference becomes even more significant.

You're better off saving up for emergencies and large expenses in an easily accessible savings account so you don't need to tap your retirement savings. A good rule of thumb would be to establish an emergency fund that can cover three to six months of living expenses. If you know you have a large purchase coming up, figure out a way to reasonably set aside money each month and begin saving well in advance.