26 U.S.C. § 6075: Time for filing estate and gift tax returns

Returns made under section 6018(a) (relating to estate taxes) shall be filed within 9 months after the date of the decedent’s death. Returns made under section 6019 (relating to gift taxes) shall be filed on or before the 15th day of April following the close of the calendar year. Any extension of time granted the taxpayer for filing the return of income taxes imposed by subtitle A for any taxable year which is a calendar year shall be deemed to be also an extension of time granted the taxpayer for filing the return under section 6019 for such calendar year. Notwithstanding paragraphs (1) and (2), the time for filing the return made under section 6019 for the calendar year which includes the date of death of the donor shall not be later than the time (including extensions) for filing the return made under section 6018 (relating to estate tax returns) with respect to such donor. filing any return under section 6018 of the Internal Revenue Code of 1986 (including any election required to be made on such a return) as such section is in effect after the date of the enactment of this Act without regard to any election under subsection (c), making any payment of tax under chapter 11 of such Code, and making any disclaimer described in section 2518(b) of such Code of an interest in property passing by reason of the death of such decedent, “shall not be earlier than the date which is 9 months after the date of the enactment of this Act.”