§ 6166. Extension of time for payment of estate tax where estate consists largely of interest in closely held business
(a) 5-year deferral; 10-year installment payment
(1) In general
If the value of an interest in a closely held business which is included in determining the gross estate of a decedent who was (at the date of his death) a citizen or resident of the United States exceeds 35 percent of the adjusted gross estate, the executor may elect to pay part or all of the tax imposed by section 2001 in 2 or more (but not exceeding 10) equal installments.
The maximum amount of tax which may be paid in installments under this subsection shall be an amount which bears the same ratio to the tax imposed by section 2001 (reduced by the credits against such tax) as—
(A) the closely held business amount, bears to
(B) the amount of the adjusted gross estate.
(3) Date for payment of installments
If an election is made under paragraph (1), the first installment shall be paid on or before the date selected by the executor which is not more than 5 years after the date prescribed by section 6151(a) for payment of the tax, and each succeeding installment shall be paid on or before the date which is 1 year after the date prescribed by this paragraph for payment of the preceding installment.