There is a prepaid tuition 529 plan which allows you to fund future college credits at the current price, according to the Securities and Exchange Commission. A college savings 529 plan, also known as an investment plan, doesn't "freeze" existing tuition prices, but allows you to invest a definite amount of money into a savings account that earns money over time.
Though you must pay normal income taxes on the dollar amount of your 529 investment plan contribution, any additional investment earnings are not taxed, according to the Marketwatch. However, because prepaid plans cannot earn money, they don't have this advantage.
A college savings 529 plan had a maximum contribution amount of more than $200,000 as of September 2010. Although no limit for a prepaid plan exists, you contribute funds into the account in a lump sum and installment format, based on the current age of the beneficiary and the number of years of college that you want to purchase.