A 529 college savings plan is a tax-advantaged investment account designed to help families save for future education expenses. Contributions to these plans can grow tax-free, and withdrawals for qualified education costs, such as tuition and books, are also tax-free. There are two main types of 529 plans: prepaid tuition plans, which allow families to prepay future tuition at current rates, and education savings plans, which let families invest in a variety of investment options. These plans are available in most states and can be used at eligible colleges and universities nationwide.