College savings plans are a great way to save for education. But not all college savings plans are great.

Most state-sponsored 529 college savings plans, which allow you to invest in a tax-advantaged account for future education costs, have improved significantly in recent years, says Madeline Hume, analyst for multi-asset and alternative strategies at investment research firm Morningstar. Plans have lowered fees, improved investment options and smoothed investment โ€œglide pathsโ€ to reduce risk.

But not every plan is keeping up. Morningstar recently downgraded eight state plans and advised most savers to avoid five others, often for excessive costs.

If youโ€™re saving for a childโ€™s education in a 529 plan, or want to start, itโ€™s a good time to review your options because there may now be a better choice.

Aim for a smooth landing

Most of the money saved in 529 plans is invested in age-weighted options that reduce exposure to stocks as the child gets closer to needing the money. In the past, 529 plans might keep the same portfolio of investments for four years or more before selling and moving into a supposedly less risky portfolio in a single day, Hume says. But those sudden movements werenโ€™t risk-free.

โ€œEspecially if thereโ€™s a large market drop on a particular day, that investor could lock in losses that may be hard to recoup,โ€ Hume says.

Today, many plans mimic target-date retirement funds, which reduce risk gradually. Even plans that still sell one portfolio of investments to buy another tend to do so more often to reduce the possibility of locking in big losses and give investors a smoother ride, she says.

Californiaโ€™s decision to move its ScholarShare College Savings plan to a progressive glide path helped earn it a gold rating this year, up from last yearโ€™s silver. Three other plans โ€“ Bright Start College Savings in Illinois, Invest529 in Virginia and my529 in Utah โ€“ also earned top marks for their glide paths, low fees and best-in-class investment options.

Look for less fees

The investment industry has been slashing costs and eliminating commissions at a โ€œdizzyingโ€ pace, so plans that havenโ€™t done so have started to look unattractive, Hume says.

Morningstar downgraded Nevadaโ€™s The Vanguard 529 College Savings Plan, a top-rated plan since 2012, from gold to silver status for this reason. Its fees remain below average but are no longer among the cheapest, Hume says.

Cost was also the reason that four other plans received negative ratings. Those plans include North Dakotaโ€™s College SAVE Plan, New Jerseyโ€™s Franklin Templeton 529 College Savings, Arkansasโ€™s GIFT College Investing Plan and Nebraskaโ€™s TD Ameritrade 529 College Savings Plan.

The fifth plan to flunk out was Nevadaโ€™s USAA College Savings Plan. Morningstar downgraded the plan after Victory Capital Holdings bought USAAโ€™s asset management business and added its own managers to all the underlying equity funds. The change happened before Nevada state officials had time to vet the changes, Hume says. Strong state oversight is a key factor in Morningstarโ€™s rating system because it deters investment firms from making money at the expense of investors.

What you should do now

You generally can change 529 providers once every 12 months without triggering IRS taxes and penalties. But youโ€™ll want to consider state tax treatment, as well.

Most states offer residents a tax break for 529 contributions and may require you to pay that back if you transfer the account to another stateโ€™s plan. If you get a tax break and your plan isnโ€™t on Morningstarโ€™s naughty list, it may make sense to stay put depending on the size of that break, the stateโ€™s policies on paying it back if you move and the planโ€™s quality. Check the planโ€™s site for details.

If your state plan did get a negative rating, you have alternatives. Many states offer more than one plan, and Nebraska, New Jersey and Nevada all have better-rated options. Also, Arkansas is one of the seven states that give a tax break for investing in any stateโ€™s plan, not just its own. (Arizona, Kansas, Minnesota, Missouri, Montana and Pennsylvania are other โ€œtax parityโ€ states.) Plus, your state could clean up its act. Florida 529 Savings Plan jumped from negative to bronze this year after revamping its plan.

Not all states offer tax breaks, of course.

If your state doesnโ€™t reward you for staying or punish you for straying, thereโ€™s little downside to moving your money to a better plan