26 CFR 11.402(e)(4)(B)-1 - Election to treat an amount as a lump sum distribution.
(a) In general. For purposes of sections 402, 403, and this section, an amount which is described in section 402(e)(4)(A) and which is not an annuity contract may be treated as a lump sum distribution under section 402(e)(4)(A) only if the taxpayer elects for the taxable year to have all such amounts received during such year so treated. Not more than one election may be made under this section with respect to an employee after such employee has attained age 59 1/2.
(b) Taxpayers eligible to make the election. Individuals, estates, and trusts are the only taxpayers eligible to make the election provided by this section. In the case of a lump sum distribution made with respect to an employee to 2 or more trusts, the election provided by this section shall be made by the employee or by the personal representative of a deceased employee.
(c) Procedure for making election -
(1) Time and scope of election. An election under this section shall be made for each taxable year to which such election is to apply. The election shall be made before the expiration of the period (including extension thereof) prescribed in section 6511 for making a claim for credit or refund of the assessed tax imposed by Chapter I of Subtitle A of the Code for such taxable year.
(2) Manner of making election. An election by the taxpayer with respect to a taxable year shall be made by filing Form 4972 as a part of the taxpayer's income tax return or amended return for the taxable year.
(3) Revocation of election. An election made pursuant to this section may be revoked within the time prescribed in subparagraph (1) of this paragraph for making an election, only if there is filed, within such time, an amended income tax return for such taxable year, which includes a statement revoking the election and is accompanied by payment of any tax attributable to the revocation. If an election for a taxable year is revoked, another election may be made for that taxable year under subparagraphs (1) and (2) of this paragraph.