Gifts are not taxable to the recipient. Your parents should be filing a gift tax return, especially if they are giving you/siblings anywhere near $10,000 or more. The actual exclusion each year is $13,000, but if they are gifting large amounts to reduce their estate, a return should be filed.
If you receive a gift it is not gross income and does not appear on your tax return. The donor may have to file a gift tax return to record the gift for estate and gift tax purposes. This is necessary only for gifts in excess of $13,000 ($26,000 for both parents together).