The 2027 Social Security cost-of-living adjustment works out to 3.6%, computed exactly the way the Social Security Administration computes it: the average CPI-W for July–September 2026 divided by the average for July–September 2025 (the third quarter of the last year a COLA was paid), rounded to the nearest 0.1%. As of 2026-10-18, all three 2026 months are actual BLS prints, so the arithmetic is final. SSA announced the COLA the morning the September CPI was released (Oct 14, 2026); this call is graded on the scoreboard.
| Month | Status | CPI-W (NSA) |
|---|---|---|
| Jul 2025 | actual (base quarter) | 316.349 |
| Aug 2025 | actual (base quarter) | 317.306 |
| Sep 2025 | actual (base quarter) | 318.139 |
| Jul 2026 | actual | 327.104 |
| Aug 2026 | actual | 328.481 |
| Sep 2026 | actual | 330.654 |
Q3 2026 average 328.746 ÷ Q3 2025 average 317.265 − 1 = 3.619% before rounding → 3.6%. CPI-W is assumed to move with CPI-U month to month (correlation of monthly changes since 2000: 0.9928; mean Q3 year-over-year gap 0.01pp, mean absolute 0.25pp).
We reproduce 47 of 51 official COLAs exactly (2000 matches the 2.4% SSA announced; SSA's series carries the corrected 2.5%); the rest differ by 0.1pp and are all pre-1985 (COLAs before 1988 were computed by SSA on the 1967=100 CPI-W. The rebased 1982-84=100 series available today carries one decimal at index levels of 50–110, so a recomputation can land 0.1pp away when the unrounded change sits near a rounding boundary; raw values are shown for every year.).
| Paid | Basis | Computed | SSA official |
|---|---|---|---|
| Jan 2026 | Q3 2025 vs Q3 2024 | 2.8% | 2.8% |
| Jan 2025 | Q3 2024 vs Q3 2023 | 2.5% | 2.5% |
| Jan 2024 | Q3 2023 vs Q3 2022 | 3.2% | 3.2% |
| Jan 2023 | Q3 2022 vs Q3 2021 | 8.7% | 8.7% |
| Jan 2022 | Q3 2021 vs Q3 2020 | 5.9% | 5.9% |
| Jan 2021 | Q3 2020 vs Q3 2019 | 1.3% | 1.3% |
| Jan 2020 | Q3 2019 vs Q3 2018 | 1.6% | 1.6% |
| Jan 2019 | Q3 2018 vs Q3 2017 | 2.8% | 2.8% |
| Jan 2018 | Q3 2017 vs Q3 2016 | 2% | 2% |
| Jan 2017 | Q3 2016 vs Q3 2014 | 0.3% | 0.3% |
| Jan 2016 | Q3 2015 vs Q3 2014 | 0% | 0% |
| Jan 2015 | Q3 2014 vs Q3 2013 | 1.7% | 1.7% |
| Jan 2014 | Q3 2013 vs Q3 2012 | 1.5% | 1.5% |
| Jan 2013 | Q3 2012 vs Q3 2011 | 1.7% | 1.7% |
| Jan 2012 | Q3 2011 vs Q3 2008 | 3.6% | 3.6% |
| Jan 2011 | Q3 2010 vs Q3 2008 | 0% | 0% |
| Jan 2010 | Q3 2009 vs Q3 2008 | 0% | 0% |
| Jan 2009 | Q3 2008 vs Q3 2007 | 5.8% | 5.8% |
| Jan 2008 | Q3 2007 vs Q3 2006 | 2.3% | 2.3% |
| Jan 2007 | Q3 2006 vs Q3 2005 | 3.3% | 3.3% |
| Jan 2006 | Q3 2005 vs Q3 2004 | 4.1% | 4.1% |
| Jan 2005 | Q3 2004 vs Q3 2003 | 2.7% | 2.7% |
| Jan 2004 | Q3 2003 vs Q3 2002 | 2.1% | 2.1% |
| Jan 2003 | Q3 2002 vs Q3 2001 | 1.4% | 1.4% |
| Jan 2002 | Q3 2001 vs Q3 2000 | 2.6% | 2.6% |
| Jan 2001 | Q3 2000 vs Q3 1999 | 3.5% | 3.5% |
| Jan 2000 | Q3 1999 vs Q3 1998 | 2.4% | 2.5% (announced 2.4%) |
| Jan 1999 | Q3 1998 vs Q3 1997 | 1.3% | 1.3% |
| Jan 1998 | Q3 1997 vs Q3 1996 | 2.1% | 2.1% |
| Jan 1997 | Q3 1996 vs Q3 1995 | 2.9% | 2.9% |
| Jan 1996 | Q3 1995 vs Q3 1994 | 2.6% | 2.6% |
| Jan 1995 | Q3 1994 vs Q3 1993 | 2.8% | 2.8% |
| Jan 1994 | Q3 1993 vs Q3 1992 | 2.6% | 2.6% |
| Jan 1993 | Q3 1992 vs Q3 1991 | 3% | 3% |
| Jan 1992 | Q3 1991 vs Q3 1990 | 3.7% | 3.7% |
| Jan 1991 | Q3 1990 vs Q3 1989 | 5.4% | 5.4% |
| Jan 1990 | Q3 1989 vs Q3 1988 | 4.7% | 4.7% |
| Jan 1989 | Q3 1988 vs Q3 1987 | 4% | 4% |
| Jan 1988 | Q3 1987 vs Q3 1986 | 4.2% | 4.2% |
| Jan 1987 | Q3 1986 vs Q3 1985 | 1.3% | 1.3% |
| Jan 1986 | Q3 1985 vs Q3 1984 | 3.1% | 3.1% |
| Jan 1985 | Q3 1984 vs Q3 1983 | 3.5% | 3.5% |
| Jan 1984 | Q1 1983 vs Q1 1982 | 3.6% | 3.5% |
| Jul 1982 | Q1 1982 vs Q1 1981 | 7.4% | 7.4% |
| Jul 1981 | Q1 1981 vs Q1 1980 | 11.3% | 11.2% |
| Jul 1980 | Q1 1980 vs Q1 1979 | 14.2% | 14.3% |
| Jul 1979 | Q1 1979 vs Q1 1978 | 9.9% | 9.9% |
| Jul 1978 | Q1 1978 vs Q1 1977 | 6.5% | 6.5% |
| Jul 1977 | Q1 1977 vs Q1 1976 | 5.9% | 5.9% |
| Jul 1976 | Q1 1976 vs Q1 1975 | 6.4% | 6.4% |
| Jul 1975 | Q1 1975 vs Q2 1974 | 8.1% | 8% |
Sources: BLS CPI-W (FRED CWUR0000SA0) and CPI-U (CPIAUCNS / CPIAUCSL), SSA's COLA rule and official series, the Nowflation Forecast. Projections, not promises. The COLA is set by the Social Security Administration with the September CPI; I-Bond rates by the Treasury for November 1 and May 1; tax-year amounts by the IRS in a revenue procedure each fall. The IRS indexes from statutory base-year amounts with cumulative factors and rounds once, so chaining from the published 2026 amounts can differ from the official 2027 figures by one rounding step ($25 / $50). Chained CPI-U initial values are revised. Not tax, benefits or investment advice. Every call is graded on the scoreboard after the announcement.
With all three third-quarter CPI-W months printed, the 2027 cost-of-living adjustment computes to 3.6% as of October 18, 2026, the way the Social Security Administration computes it; nothing in the calculation is projected.
SSA divides the average CPI-W for July, August and September 2026 by the same average for 2025 (the third quarter of the last year a COLA was paid) and rounds to the nearest 0.1%. The base-quarter average is 317.265; the current-quarter average is 328.746.
October 14, 2026 — SSA announced the COLA the morning the September CPI was released. This call was on the record before that date and is graded on the scoreboard.
2.8%, paid from Jan 2026, on a Q3 2025 CPI-W average of 317.265 against 308.729 for Q3 2024. Recomputing every automatic COLA since 1975 from the published CPI-W reproduces 47 of 51 of SSA's official figures exactly.