When choosing an investment, many people immediately zero in on past performance. It’s an easy-to-understand metric, and when given a choice between a mutual fund with higher returns and another with lower returns, it’s intuitive to gravitate toward the former.

But when it comes to choosing a 529 college savings plan for a child or grandchild, consider other factors first, some 529 plan experts say.

“People should not chase performance,” says David Smith, a wealth advisor and co-chief investment officer with Robinson Smith Wealth Advisors in Portsmouth, New Hampshire. Smith explains that different asset classes move in and out of favor, and last year’s red-hot investment may have cooled off.

“There’s quite a disparity between U.S. and international stock performance over the last six years. Some [state 529] plans, like New York, don’t offer any international exposure. That’s really benefited them because the U.S. stock market has performed twice as well as developed international [markets],” he says.

Eventually that balance will shift, and plans with more international exposure may show better performance than those holding only domestic stocks.

[See: 6 Essential Questions to Ask Before Choosing a 529 Plan.]

Andrea Feirstein, managing director at AKF Consulting Group, which counts 33 college savings plans as clients, agrees that performance is not the best benchmark for making a plan choice. A list of best-performing and worst-performing plans may be misleading, she says.

“Let’s say I’m a family that has just come into an inheritance, and I haven’t been saving enough money. Now I have an extra $100,000. My child is 16, and I’m looking at a plan with a return of 10.52 percent,” she says.

A very aggressive allocation can deliver a higher return, but it also carries more risk. For that reason, Feirstein says, “that 10.52 percent may not be an appropriately allocated portfolio for the time horizon of a 16-year-old.”

She emphasizes that a basic list of best- and worst-performing plans does not provide enough information for a parent or grandparent to make a decision. “You have to know exactly what you are comparing when you are looking at plans,” she says.

Many 529 plans feature age-based glide paths that automatically reallocate as the beneficiary approaches college age. With a younger child, the objective is growth. The older the beneficiary, the more crucial it is to preserve capital. Those are entirely different investment objectives.

In addition, many plans offer single-fund options or non-age-based portfolios. Simply averaging a plan’s overall return won’t tell a potential buyer anything about the appropriateness of the specific options within that plan, Feirstein points out.

Joseph Hurley, founder of 529 plan research site SavingForCollege.com, says rather than first focusing on performance of plans throughout the country, parents and grandparents should investigate the tax advantages of their home state’s plan.

[Read: How to Find the Best 529 College Savings Plan for You.]

If the beneficiary is a teenager nearing college, a state tax advantage could outweigh a plan with better performance in the past three to five years. “First check out your state’s plan, then start shopping around,” Hurley advises.

Thirty-four states offer a tax benefit for residents who invest in their plans. Some states offer other perks to participants. For example, in New Jersey, many beneficiaries qualify for a small scholarship at an in-state college or university.

If an investor finds that his or her state doesn’t offer any tax benefit for the 529 plan, performance may be a factor to consider, Feirstein says. However, she emphasizes investors should evaluate costs along with performance when looking at an out-of-state plan.

Hurley says plan buyers should also be cognizant of fees and expenses. “Certainly, performance is one of the key items, but it’s difficult to compare performance of plans if you’re doing this on your own. It’s easier to compare fees on your own, and that’s an important factor as well, especially if the investments in two different plans are fairly similar,” he says.

High fund management fees, or a fee paid to an advisor, can chip away at returns. In almost all cases, an indexed, or passive, strategy will have lower costs than an active strategy, in which managers are trying to pick investments that will perform the best. That’s why it’s so important for investors to understand the underlying philosophy before choosing a fund, Smith says.

[Read: 529 Plans: Should You Choose Static or Age-Based?]

Of actively managed plans available, some will show a clear excess return in some years but can significantly underperform in others. Smith says the active managers “have a lot of leeway to make long calls, but in a one-, two- or three-year time period, their style could be out of favor and you may find them in those worst-performing portfolios.”

Smith has some advice for parents and grandparents who want to optimize their 529 returns: Start as early as possible. “The biggest mistake people make is not getting started,” he says.

With time and the magic of compounding, a portfolio with lesser performance can deliver the same, or better, result than a more aggressive portfolio invested for a shorter duration.

Smith advocates investing a small amount, just to get the ball rolling. “A lot of plans will let you start with $25 a month, and they’ll waive fees for automatic saving on a monthly basis. Twenty-five dollars a month will add up over time, and slowly raise that amount if you can. Getting started early will help you overcome the returns of a 529 with just an average performance,” he says.

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Parents: When Investing in a 529 Plan, Look Beyond Performance originally appeared on usnews.com