(5) Election to use 10-percent method (A) General rule In the case of any long-term contract with respect to which an election under this paragraph is in effect, the 10-percent method shall apply in determining the taxable income from such contract. (B) 10-percent method For purposes of this paragraph— (i) In general The 10-percent method is the percentage of completion method, modified so that any item which would otherwise be taken into account in computing taxable income with respect to a contract for any taxable year before the 10-percent year is taken into account in the 10-percent year. (ii) 10-percent year The term “10-percent year” means the 1st taxable year as of the close of which at least 10 percent of the estimated total contract costs have been incurred. (C) Election An election under this paragraph shall apply to all long-term contracts of the taxpayer which are entered into during the taxable year in which the election is made or any subsequent taxable year. (D) Coordination with other provisions (i) Simplified method of cost allocation This paragraph shall not apply to any taxpayer which uses a simplified procedure for allocation of costs under paragraph (3)(A). (ii) Look-back method The 10-percent method shall be taken into account for purposes of applying the look-back method of paragraph (2) to any taxpayer making an election under this paragraph.