5 CFR § 591.209 - What is a price index?
---
identifier: "/us/cfr/t5/s591.209"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "5 CFR § 591.209 - What is a price index?"
title_number: 5
title_name: "Administrative Personnel"
section_number: "591.209"
section_name: "What is a price index?"
chapter_name: "OFFICE OF PERSONNEL MANAGEMENT"
subchapter_number: "B"
subchapter_name: "CIVIL SERVICE REGULATIONS"
part_number: "591"
part_name: "ALLOWANCES AND DIFFERENTIALS"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
cfr_part: "591"
---
# 591.209 What is a price index?
(a) The price index is the COLA area price divided by the DC area price and multiplied by 100.
(b) Example:
COLA Area Average Price for Item A = $1.233
DC Area Average Price for Item A = $1.164
Computation:
$1.233/$1.164 = 1.0592783
1.0592783 × 100 = 105.92783.
(c) In the case of the final index, OPM rounds the index to two decimal places.