The purpose of Form 1099-Q is to remind you – and alert the IRS – that you made a withdrawal from a 529 college savings plan, state prepaid tuition program, or Coverdell education savings account.
The distribution that is reported in box 1 of the 1099-Q is tax-free if you used the money to pay tuition and related fees, books, and room and board. The tax-free distribution withdrawals for qualified expenses must be reduced by other tax-free educational benefits before calculating the tax-free withdrawals. If you use the funds for other purposes, then only the earnings portion of the distribution is taxable. That amount is listed in box 2 of the 1099-Q and should be reported by you as "other income" on line 21 of the 1040 form you file for the year of the distribution. The taxable portion also is subject to a 10 percent penalty tax that is calculated on Form 5329.
The 1099-Q's main purpose is to alert an IRS agent to the distribution in the event you are audited. The agent can then ask how the funds were used and determine if you reported the distribution as necessary.