2027 COLA tracker: CSRS, FERS, and Social Security
One of the three months that set the 2027 cost-of-living adjustment is in. This page carries the running calculation, the two scenarios that bracket it, the FERS reduced-formula result, the Part B offset, and a calculator for your own annuity. It is updated on each release date: September 11 for August, October 14 for September, when the number becomes final.
1. The running calculation
| Counting month | CPI-W (1982–84 = 100) | vs. Q3 2025 baseline of 317.265 | Status |
|---|---|---|---|
| July 2026 | 327.104 | +3.10% | Final (released Aug 12) |
| August 2026 | — | — | Pending Sept 11 |
| September 2026 | — | — | Pending Oct 14 |
| Q3 2026 average (running) | 327.104 | +3.1% | One of three months in |
Read the running figure carefully. It is not a forecast. It is what the COLA would be if the index did not move for two months. It moves up if August and September rise, which they usually do, and it rounds to the nearest tenth of a percent only after all three months are averaged.
2. How the COLA is computed
The 2027 COLA is the percentage increase in the average CPI-W for July, August, and September 2026 over the average for the same three months of 2025, rounded to the nearest tenth. The 2025 third-quarter average, 317.265, is the baseline. That baseline is higher than July 2025 alone (316.349) because prices rose through last summer, which is why the July-to-July change of 3.4% overstates the running COLA of 3.1%: the comparison is against a three-month average that already includes August and September 2025.
Running: (327.104 − 317.265) ÷ 317.265 = 3.10%
The same percentage applies to Social Security, CSRS, CSRS Offset, and military retired pay. FERS applies it through the reduced formula in section 4. For the full mechanics, including how COLAs are prorated and when they stop and start, see FERS and CSRS COLAs explained and the Social Security COLA.
3. Scenarios: flat, seasonal, and the forecasters
| Scenario | Aug–Sep CPI-W average needed | 2027 COLA, CSRS / Social Security | 2027 FERS COLA | Monthly gain on $2,071 (avg. SS benefit) |
|---|---|---|---|---|
| Flat: August and September equal July | 327.104 | 3.1% | 2.1% | $64 |
| Modest seasonal rise (+0.2% / month) | ~328.1 | 3.3% | 2.3% | $68 |
| Senior Citizens League model (August) | ~329.5 | 3.6% | 2.6% | $75 |
| Strong rise (+0.7% / month) | ~330.4 | 3.8% | 2.8% | $79 |
| For reference: 2026 COLA | — | 2.8% | 2.0% | $58 |
Twelve-month CPI-W inflation was 3.4% in July, down slightly from 3.5% in June. A COLA in the 3.1% to 3.6% range is the realistic bracket; anything above 3.8% would require a sharp late-summer jump that the monthly data has not shown. Every scenario above is larger than the 2.8% paid for 2026.
4. The FERS reduced formula
FERS annuitants do not receive the full CPI-W increase once it exceeds 2%. Under 5 U.S.C. § 8462(b):
| CPI-W increase | FERS COLA | Example |
|---|---|---|
| 2.0% or less | Same as CPI-W | 1.7% → 1.7% |
| 2.1% to 3.0% | 2.0% | 2.8% → 2.0% (the 2026 COLA) |
| Above 3.0% | CPI-W minus 1.0 point | 3.1% → 2.1%; 3.6% → 2.6% |
Two further FERS rules. Regular FERS retirees receive no COLA until age 62; the first one arrives in the January after the 62nd birthday, prorated if applicable. Disability and survivor annuitants receive COLAs at any age. CSRS retirees and CSRS Offset retirees receive the full COLA at any age. The gap between the CSRS and FERS figures is the reason a FERS pension loses ground to inflation over a long retirement, which the diet-COLA erosion guide quantifies.
5. Your number
Enter your monthly annuity or benefit and the COLA percentage. The default is the running 3.1%; change it on September 11 and October 14, or to test a scenario.
6. The Part B offset
For most retirees the Medicare Part B premium is deducted from the same check the COLA is added to. The 2025 Medicare Trustees Report projects the standard 2027 premium at $218.60, up $15.70 from $202.90; CMS sets the actual figure in November, and recent years have come in above the projection. On the average Social Security benefit of $2,071, a 3.1% COLA is $64 before Part B and about $48 after. On a $1,500 FERS annuity at the 2.1% reduced rate, the COLA is $31.50 and the Part B increase takes half of it.
Social Security’s hold-harmless rule guarantees that a Part B increase cannot reduce a check below its prior amount, but it protects only Social Security payments (not CSRS or FERS annuities) and only beneficiaries who are not paying an IRMAA surcharge. For the full net-check arithmetic see the Part B projection dispatch.
7. Who gets it, when, and how much is prorated
- Effective date: December 1, 2026. Paid: the annuity payment dated January 2027 (OPM) and the January 2027 Social Security payment.
- Full COLA: anyone whose annuity or benefit was in pay for the full year before December 1, 2026.
- Prorated: anyone whose annuity began during 2026 receives one-twelfth of the COLA for each month the annuity was in pay before December 1. A retiree whose annuity began July 1, 2026 receives 5/12 of the adjustment. This is one input into the December-vs-January decision.
- FERS under 62: no COLA, except disability and survivor annuitants. The FERS supplement is never adjusted for COLA.
- Active employees: the COLA has nothing to do with the January pay adjustment, which under the 2027 alternative pay plan is zero for most civilian employees.
8. Update log
| Date | Release | Running COLA (CSRS / FERS) |
|---|---|---|
| Aug 12, 2026 | July CPI-W 327.104 | 3.1% / 2.1% |
| Sep 11, 2026 | August CPI-W | Pending |
| Oct 14, 2026 | September CPI-W; SSA announcement | Pending: final |
9. Frequently asked questions
What is the 2027 COLA estimate right now?
With one of the three counting months in, the July 2026 CPI-W of 327.104 is 3.1 percent above the third-quarter 2025 baseline of 317.265. If August and September come in flat, the 2027 COLA is 3.1 percent for CSRS and Social Security and 2.1 percent for FERS. Forecasters who model a normal seasonal rise in August and September put it between 3.4 and 3.8 percent. The August figure is released September 11 and the final number on October 14.
Why is the FERS COLA lower than the CSRS COLA?
By law, FERS annuities receive the full CPI-W increase only when it is 2 percent or less. When the increase is between 2 and 3 percent, FERS receives 2 percent. When it is above 3 percent, FERS receives the increase minus one percentage point. A 3.1 percent CSRS COLA is a 2.1 percent FERS COLA; a 3.6 percent CSRS COLA is a 2.6 percent FERS COLA. FERS retirees under 62 receive no COLA at all except disability and survivor annuitants.
When will I see the 2027 COLA in my payment?
The COLA is effective December 1, 2026 and appears in the annuity payment dated January 2027 for CSRS and FERS retirees and in the January 2027 Social Security payment. Retirees whose annuity began during 2026 receive a prorated COLA, one-twelfth for each month the annuity was in pay before December 1.
Will the Medicare Part B increase cancel out the COLA?
Partly, for anyone whose Part B premium is deducted from their check. The Medicare Trustees project the standard 2027 Part B premium at about $218.60, up $15.70 from $202.90. On the average Social Security benefit of about $2,071, a 3.1 percent COLA is about $64 a month before the Part B increase and about $48 after it. The hold-harmless rule prevents the Part B increase from reducing a Social Security check below its prior amount, but it does not apply to CSRS or FERS annuities or to anyone paying IRMAA.
- BLS, Consumer Price Index: CPI-W, July 2026 release (August 12, 2026) and release schedule
- SSA Office of the Chief Actuary, COLA computation and the 2026 COLA (2.8%; Q3 2025 CPI-W average 317.265)
- 5 U.S.C. § 8462, FERS cost-of-living adjustments (reduced formula; age 62 rule)
- OPM, cost-of-living adjustments: effective date, payment, proration
- 2025 Medicare Trustees Report, projected 2027 Part B premium
- SSA, 2026 COLA fact sheet (average retired-worker benefit)