5 CFR § 591.226 - How does OPM apply the CPIs?

---
identifier: "/us/cfr/t5/s591.226"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "5 CFR § 591.226 - How does OPM apply the CPIs?"
title_number: 5
title_name: "Administrative Personnel"
section_number: "591.226"
section_name: "How does OPM apply the CPIs?"
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"
---


# 591.226 How does OPM apply the CPIs?

(a) OPM uses a three-step process to adjust price indexes by relative annual or biennial changes in the CPIs. For steps 1 and 2, OPM computes the annual change by dividing the CPI from 1 year after the survey by the CPI from the time of the survey. OPM computes the biennial change by dividing the CPI from 2 years after the survey by the CPI from the time of the survey.

(1) *Step 1.* OPM computes the annual or biennial CPI change for the COLA area.

(2) *Step 2.* OPM computes the annual or biennial CPI change for the DC area.

(3) *Step 3.* OPM multiplies the COLA area price index from the last survey by the COLA area CPI change computed in step 1 divided by the DC area CPI change computed in step 2. The adjusted price index is rounded to the second decimal place.

(b) *Example:*

|  | 2008 | 2009 |
| --- | --- | --- |
| COLA Area CPI | 172.2 | 174.7 |
| DC Area CPI | 159.7 | 161.9 |
| COLA Area Survey Index | 117.33 | () |
| COLA Area CPI Adjusted Index | () | 117.42 |
| No survey. |  |  |
| N/A |  |  |

Computation:

117.33 × (174.7/172.2)/(161.9/159.7) = 117.4159, which would round to 117.42.