The 2027 401(k) Limit Is Projected Near $25,000 — Here's How to Plan Around It Before the IRS Confirms
Milliman projects the 2027 401(k) elective deferral limit at roughly $25,000, up from $24,500 in 2026. Here's what's projected vs. already official, and how to pace your contributions either way.
Milliman's actuarial forecast projects the 2027 elective deferral limit at roughly $25,000, up from the confirmed $24,500 in 2026. It's a forecast based on inflation data available so far — the IRS typically confirms the actual number in November.
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About the Author
Sujit KarkiFinance Researcher & Market Analyst
Independent finance researcher and market analyst with expertise in macroeconomics, equity markets, and personal finance. I help regular investors make better-informed decisions through rigorous, data-driven analysis.
Retirement account contribution limits get one round of real news each year — the IRS's official announcement, usually in November — but actuarial forecasts start circulating months earlier. Here's what's projected for 2027, what's already locked in, and how to plan around the uncertainty without overcommitting to a number that might shift.
Key Takeaways
Milliman projects the 2027 401(k) elective deferral limit at roughly $25,000, up from $24,500 in 2026.
The IRA contribution limit is forecast to hold roughly steady rather than rise significantly.
2027 HSA contribution limits are already official: $4,500 self-only and $9,000 family coverage.
All 401(k)/IRA figures for 2027 are projections until the IRS's official November announcement.
Frontloading contributions early in the year can cause you to miss months of employer match if your plan doesn't true up.
What's projected for 2027
Milliman's actuarial forecast projects the 2027 401(k) elective deferral limit at roughly $25,000, up from the confirmed $24,500 in 2026. The "super catch-up" for savers age 60–63 is projected to rise to roughly $11,750, while the regular age-50 catch-up is expected to hold near $8,000. The overall defined-contribution limit, including employer contributions, is projected near $75,000.
Limit
2026 (confirmed)
2027 (projected)
401(k) elective deferral
$24,500
~$25,000
Catch-up (age 50+)
$8,000
~$8,000
Super catch-up (age 60–63)
$11,250
~$11,750
IRA limit
$7,500
~$7,500 (roughly flat)
What's official vs. what's a forecast
It's worth being precise here, because these two categories get blurred in a lot of coverage. The 401(k) and IRA numbers above are forecasts, built from inflation data available through mid-year — the IRS sets the real numbers later, typically in a November notice. HSA limits work on a different, earlier timeline: the 2027 HSA limits are already official at $4,500 for self-only coverage and $9,000 for family coverage, since the IRS confirms those well ahead of the calendar year.
Warning
Don't set a permanent payroll contribution percentage based on the 401(k) forecast alone. Actuarial projections are generally close, but they've been revised before once real inflation data came in. Plan around the forecast, then confirm and adjust once the IRS makes it official.
Why I'm citing a forecast here instead of computing it myself
On the 2027 tax brackets and the 2027
Social Security COLA I ran the government's own
formula against published inflation data rather than repeating anyone's estimate.
The obvious question is why I don't do that here.
I tried. It doesn't work, and the reason is worth understanding before you trust
any "just apply inflation to last year's limit" arithmetic you find elsewhere.
The natural approach is to take the current limit and scale it by the year's
inflation. Retirement plan limits are indexed to CPI-U measured over the quarter
ending 30 September, so test that method against a year where the answer is
already known:
Back-test: predicting the known 2026 limit from 2025
Step
Value
CPI-U, Q3 2024 average
314.8790
CPI-U, Q3 2025 average
323.9413
Year-over-year increase
2.878%
$23,500 × 1.02878
$24,176
Rounded down to the nearest $500
$24,000
What the IRS actually announced
$24,500
Off by $500. The limit rose 4.26% while CPI-U over the measurement quarter
rose 2.88% — the increase was roughly half again as large as the inflation that
supposedly drove it.
That is not an error in the inflation data. It is how the indexing works.
Retirement limits are not scaled from last year's rounded figure; they are
computed from a fixed statutory base period and then rounded down to a $500
increment. The remainder that gets truncated away doesn't vanish — it stays in
the running total and eventually pushes the figure over the next $500 step. So
the published limits move in lumpy jumps that don't track any single year's
inflation, and a year-over-year calculation drifts further off with every
rounding.
Warning
This is the practical lesson: the same method is not valid for every
inflation-indexed figure. The COLA and the tax brackets scale cleanly year over
year, so anyone can verify them. Retirement contribution limits do not. If you
see an article projecting next year's 401(k) limit by applying a CPI figure to
this year's number, it is using a method that demonstrably fails against a year
we can check — and it will usually be low.
That's why the figure at the top of this post comes from Milliman rather than
from me. Actuarial firms model the full base-period calculation, and this is a
case where citing someone with the proper model beats rolling your own
arithmetic. I'd rather show you a verified reason to trust a source than a
homemade number that fails its own back-test.
The limit history in context
The trend has been a steady climb tied to inflation, with the occasional larger jump. The projected 2027 increase is modest relative to some recent years — a sign that the inflation data feeding the formula has been cooling too.
Don't frontload past the match
Maxing out your 401(k) by, say, June feels efficient, but it carries a real risk: if your employer contributes its match per paycheck rather than "truing up" at year-end, front-loading contributions early can mean you stop contributing before the year ends — and miss months of employer match on the paychecks after you hit your personal limit.
Check your specific plan document — some employers do true up annual match regardless of timing, which removes this risk entirely. Many don't.
Pace your per-paycheck contribution
Interactive · pace your contributions
How much per paycheck to hit the limit
Annual limit target$25,000
Already contributed this year$0
Paychecks remaining this year20
With $0 left to contribute over 20 paychecks, that's $0/paycheck.
Progress toward the limit$0 / $25,000
The 2027 limit shown as a default is a Milliman forecast — the IRS typically confirms the official figure in November. Don't set payroll elections around a projection alone once the real number is out.
Confirm whether your plan trues up the match annually before deciding whether to front-load contributions at all.
Set your contribution rate as a percentage or flat per-paycheck dollar amount that spreads evenly across the year, unless you've confirmed true-up protection.
If you're 60–63, understand the mandatory Roth catch-up rule before assuming pre-tax catch-up contributions are still available to you — see my mandatory Roth catch-up breakdown.
Revisit your contribution elections once the IRS confirms the real 2027 numbers, typically in November — don't "set and forget" on a forecast.
Milliman's actuarial forecast projects the 2027 elective deferral limit at roughly $25,000, up from the confirmed $24,500 in 2026. It's a forecast based on inflation data available so far — the IRS typically confirms the actual number in November.
Sujit Karki|||5 min read