Many individuals elected to make gifts in 2012. The intent was to utilize the $5M exemption during their lifetime which is not subject to estate or gift taxes. If you made gifts more than $13,000 to any individual ($26,000 by a married couple) you must file a gift tax return (IRS Form 709) no later than April 15, 2013. If you need more time to complete the gift tax return you need to file Form 4868 before your taxes are due. This will extend the deadline for both your income tax return and the gift tax return to October 15th.
If you made gifts of family partnership interests or real property using the annual $13,000 exclusion and you took a discount or a low value on the gift you should file a gift tax return and provide the information on the gift to the IRS. The filing of the gift tax return will start the statute of limitations for a review of the discounted gift you made to a family member.