The Postal Service may adjust rates based upon changes in the Consumer Price Index for all Urban Consumers (CPI-U) identified in § 3030.141. If rate adjustment filings involving rate increases are filed 12 or more months apart, rate adjustments are subject to a full year limitation calculated pursuant to § 3030.142. If rate adjustment filings involving rate increases are filed less than 12 months apart, rate adjustments are subject to a partial year limitation calculated pursuant to § 3030.143.

The monthly CPI-U values needed for the calculation of rate adjustment limitations under this subpart shall be obtained from the Bureau of Labor Statistics (BLS) Consumer Price Index—All Urban Consumers, U.S. All Items, Not Seasonally Adjusted, Base Period 1982-84 = 100. The current Series ID for the index is “CUUR0000SA0.”

(a) If a rate adjustment filing involving a rate increase is filed 12 or more months after the most recent rate adjustment filing involving a rate increase, then the calculation of an annual limitation for the class (full year limitation) involves three steps. First, a simple average CPI-U index is calculated by summing the most recently available 12 monthly CPI-U values from the date of the rate adjustment filing and dividing the sum by 12 (Recent Average). Second, a second simple average CPI-U index is similarly calculated by summing the 12 monthly CPI-U values immediately preceding the Recent Average and dividing the sum by 12 (Base Average). Third, the full year limitation is calculated by dividing the Recent Average by the Base Average and subtracting 1 from the quotient. The result is expressed as a percentage, rounded to three decimal places.

(b) The formula for calculating a full year limitation for a rate adjustment filing filed 12 or more months after the last rate adjustment filing is as follows: Full Year Limitation = (Recent Average/Base Average)−1.

(a) If a rate adjustment filing involving a rate increase is filed less than 12 months after the most recent rate adjustment filing involving a rate increase, then the annual limitation for the class (partial year limitation) will recognize the rate increases that have occurred during the preceding 12 months. When the effects of those increases are removed, the remaining partial year limitation is the applicable restriction on rate increases.

(b) The applicable partial year limitation is calculated in two steps. First, a simple average CPI-U index is calculated by summing the 12 most recently available monthly CPI-U values from the date of the rate adjustment filing and dividing the sum by 12 (Recent Average). Second, the partial year limitation is then calculated by dividing the Recent Average by the Recent Average from the most recent previous rate adjustment filing (Previous Recent Average) applicable to each affected class of mail and subtracting 1 from the quotient. The result is expressed as a percentage, rounded to three decimal places.

(c) The formula for calculating the partial year limitation for a rate adjustment filing filed less than 12 months after the last rate adjustment filing is as follows: Partial Year Limitation = (Recent Average/Previous Recent Average)−1.