Best 529 plans for the long haul

May 29 is 529 day, and with graduation season upon us, it's the perfect time to take a look at the best 529 college savings plans.

With nearly every state and the District of Columbia offering at least one 529 plan, investors have dozens of choices, and assets in the plans increased 9.1 percent in 2014 to $249.7 billion, according to College Savings Plan Network. Earnings on contributions are not taxable, nor are withdrawals to pay for qualified higher education expenses.

It's important to make sure that the expenses you are covering actually qualify under your 529 plan. (There are special rules for off-campus housing, for example.) You are also limited in how often you can adjust your asset allocation, and some plans come with significant fees. But the tax advantages and the inexorable rise in college costs make 529 plans an attractive option for college savers.

Read More529 balances are growing, but so are college costs

The following are the top 529 savings plans over the past 10 years that do not require state residency to invest, ranked by savingforcollege.com.

-—By Kelley Holland, special to CNBC.com
Posted 28 May 2015

Investment options in this Utah plan include Vanguard and Dimensional funds, a fixed income fund from the state treasurer and an FDIC–insured account. There are also four age-based investment options, which reallocate assets more conservatively as the beneficiary approaches college age. It scores a 4.9 out of 5 with savingforcollege.com for its reliability, and 3.99 on performance.

New York's plan uses Vanguard mutual funds and lets investors link their accounts to the Upromise rewards service, which lets users earn cash back for college from participating merchants. The plan charges a low annual asset-based fee of 0.16 percent of account assets. Its performance over 10 years gets 4.61 out of 5 from savingforcollege.com, and its reliability gets a perfect 5. There are static investment options and age-based ones that grow more conservative over time.

The inVEST 529 plan in Virginia offers mutual funds from Vanguard and Parnassus. Investors have a choice of age-based investment options that automatically shift toward conservative assets as college nears, and nine static investment portfolios. It scores 4.1 out of 5 for reliability with savingforcollege.com and 4.06 for costs.

As the name suggests, Nevada's 529 plan uses USAA mutual funds. Accounts can link to the Upromise rewards service, which offers cash back for college from participating merchants. Investors can choose an age based investment option or use static investments in different USAA funds. The plan earns a 4.6 out of 5 for reliability and 3.69 for costs.

Alaska's nationally branded 529 plan mimics its University of Alaska College Savings Program except for that plan's special features for University of Alaska students. Both use T. Rowe Price funds and offer age-based (or "enrollment-based") investment options that grow more conservative over time, along with static investment options. The nationally branded plan scores 4.8 out of 5 for reliability and 4.59 on performance.

Unlike many 529 plans, the Florida 529 Savings Plan uses money management firms to manage its investment pools. Investors can use age-based investment options that grow more conservative as college nears, or static investment options including eight individual investment funds and three pre-designed investment portfolios. The plan scores 4.05 out of 5 for performance.

This 529 plan from Ohio offers a wide array of investment options. In addition to three age-based options that grow more conservative as a beneficiary nears college age, there are 14 static investment options using Vanguard funds, two kinds of FDIC-insured deposit accounts, and other static investment options from PIMCO and GE Asset Management. It nets a 4.57 score out of 5 for features and 4.2 for reliability.

This Iowa plan features Vanguard mutual funds. Investors can choose age based investment options that shift to more conservative assets over time, or static investment options including 10 individually customizable portfolios and four age-based portfolio options. Accounts can link to the Upromise rewards service, offering cash back for college from participating merchants. The plan scores 4.8 out of 5 for reliability and 4.22 for costs.

This 529 plan from Maryland offers 14 different investment options ranging from more aggressive to more conservative investment strategies. You can invest in multiple portfolios, and can also move your investment among portfolios twice per calendar year. The plan scores 4.6 out of 5 for reliability and 3.87 for performance.

Kansas' plan is managed by American Century and features three age-based investment options with American Century and Vanguard funds and one with Vanguard index funds. (These investment options shift into more conservative assets as college nears.) There are also several static investment options, including the tobacco-free One Choice Portfolios. The plan scores 4 out of 5 for reliability and 3.88 for costs.