Top-Rated 529 College Savings Plans: Savingforcollege.com

(Related: 30 Best Paying College Majors: 2017)

Performance is one of several criteria that families should use when choosing a 529 fund, whose earnings and distributions are tax-free so long as the funds are used for education. Fees are another consideration as well as tax treatment. Some plans offer a tax benefit – credit or deduction – for state residents if they invest in that state's plan; others offer a tax benefit for residents no matter what plan they choose. It's incumbent on families to do that research, and Savingforcollege.com as well as other websites including cappex.com and morningstar.com, which offer useful comparative research for that purpose.

Fees for 529 plans have been declining, according to another recent study from Savingforcollege.com. The study found that the mean fees for direct-sold plans, which include expense ratios as well as account maintenance investment management fees, fell 3.7% over the past six months. (Fees for advisor-sold plans are more complex and not included in the study but they are disclosed in another part of the website).

The fee study compared the total costs of all direct-sold 529 plans based on a hypothetical investment of $10,000 earning 5% annually over 10 years, and highlighted the lowest-cost and highest-cost investment options for each plan. It includes annual account fees, if any, but some families need to keep in mind that some plans will waive such fees if the plan owner sets up automatic contributions or has high account balances.

Fees and expenses can have a significant impact on a college-savings fund but should not be the only factor families use when selecting a 529 plan, according to savingforcollege.com. Performance, state tax benefits and investment options should also be considered as well as eligibility (some funds are available only to state residents.)

In addition, higher fees don't necessarily mean poorer performance. The Tributary Small Company portfolio offered through TD Ameritrade has a projected 10-year cost of over $1,768 but its portfolio gained 22.3% over the one-year ended June 30, 2017.

 "Before investing in a 529 plan, you should read the plan's official program description in its entirety," according to Savingforcollege.com.

— Related on ThinkAdvisor:

• 16 Best & Worst 529 College Savings Plans of 2016: Morningstar
• 30 Best Paying College Majors: 2017
• 31 Worst Paying College Majors: 2017