A gift of any size is not reported on your income tax return.
If the gift had a value of $17,000 or less, the gift is not taxable to you or to the recipient. (For married couples, the limit is $34,000.)
If the gift was worth more than $17,000 ($34,000 for married couples), you must file Form 709: U.S. Gift (and Generation-Skipping Transfer) Tax Return, which is due April 15 of the following year. Even if you do not owe a gift tax because you have not reached the $12.92 million lifetime limit, you are still required to file this form if you made a gift that exceeds the $17,000/$34,000 annual gift tax exclusion level. The IRS needs to keep a running tab of your lifetime exemption.
Read more about this here: TurboTax Tax Tips: The Gift Tax