Weighted average

The monthly national average monthly bid amount computed under subparagraph (A) for a year shall be a weighted average, with the weight for each plan being equal to the average number of part D eligible individuals enrolled in such plan in the reference month (as defined in section 1395w–27a(f)(4) of this title ).

For purposes of applying this paragraph for 2006, the Secretary shall establish procedures for determining the weighted average under clause (i) for 2005.