Distributions must otherwise be includible

An amount shall be treated as a distribution for purposes of paragraph (1) only to the extent that such amount would be includible in gross income without regard to paragraph (1).

Notwithstanding section 72, in determining the extent to which an amount is treated as a distribution for purposes of subparagraph (A), the aggregate amounts distributed from an eligible retirement plan in a taxable year (up to the amount excluded under paragraph (1)) shall be treated as includible in gross income (without regard to subparagraph (A)) to the extent that such amount does not exceed the aggregate amount which would have been so includible if all amounts to the credit of the eligible public safety officer in all eligible retirement plans maintained by the employer described in paragraph (4)(B) were distributed during such taxable year and all such plans were treated as 1 contract for purposes of determining under section 72 the aggregate amount which would have been so includible. Proper adjustments shall be made in applying section 72 to other distributions in such taxable year and subsequent taxable years.