§ 4206.5 Amount of credit in plans using the modified presumptive method.

(a) General. In a plan that uses the modified presumptive method described in section 4211(c)(2) of ERISA, the credit shall equal the sum of the unamortized old liabilities determined under paragraph (b) of this section, multiplied by the fractions described or determined under paragraph (c) of this section. When an employer's prior partial withdrawal liability has been reduced or waived, this credit shall be adjusted in accordance with § 4206.8.

(b) Unamortized old liabilities. The amounts described in this paragraph shall be determined as of the end of the plan year preceding the withdrawal for which the credit is being calculated, and are the employer's proportional shares, if any, of—