2027 Retirement Contribution Limits: 401(k), IRA & HSA

2027 Retirement Contribution Limits: What's Confirmed vs Projected

Every autumn, the IRS announces the following year's retirement contribution limits — but HSA limits work on a different schedule and are already locked in for 2027. Here's where things stand as of September 2026:

• HSA limits: already official. The IRS released 2027 HSA and HDHP limits via Revenue Procedure 2026-24 on May 29, 2026 — months ahead of the other limits, because HSA amounts are indexed under a separate statutory formula (IRC §223) that doesn't wait for the same year-end calculation.
• 401(k), 403(b), 457, and IRA limits: still projected. These follow IRC §402(g) and §219, calculated from a full year of Consumer Price Index data that isn't complete until September 2026 — the IRS typically announces them in October or November for the following tax year.

This guide covers both: the confirmed 2027 HSA figures, and the current best projections for 401(k) and IRA limits from Milliman, one of the most-cited independent actuarial forecasters for this exact purpose. We'll update the projected sections with official numbers the moment the IRS publishes them.

2027 401(k), 403(b) & 457 Limits — Projected

Based on Milliman's most recent forecast (June 2026, using trailing 12-month CPI through Q2 2026), here's how 2027 compares to the confirmed 2026 limits:

These limits apply to 401(k), 403(b), and most 457(b) governmental plans, as well as the federal Thrift Savings Plan. The deferral limit and catch-up amounts are shared across Roth and traditional contributions to the same plan type — they aren't separate buckets.

A methodology note: earlier 2026 forecasts (published in March 2026) projected a smaller increase — around $25,000 for the deferral limit and a flat $8,000 catch-up. Milliman's more recent June forecast, based on more complete CPI data, revised these upward. The final September CPI reading (published in October) could still shift the actual IRS figure slightly from either estimate.

2027 IRA Contribution Limits — Projected, and Genuinely Uncertain

The 2026 IRA contribution limit is confirmed at $7,500, with a $1,100 catch-up for savers 50 and older (total $8,600) — both verified directly against the IRS's own 2026 announcement.

For 2027, forecasters are genuinely divided — this isn't a case where we're picking one estimate and calling it settled. The IRA limit adjusts in $500 increments only when cumulative inflation crosses a specific threshold, and as of the most recent available data, the projected figure sits right at that boundary. Some models keep it flat at $7,500 for 2027; others, using slightly more recent CPI data, project it rounds up to $8,000. Which one happens depends on the final September 2026 CPI reading the IRS will use for the actual calculation — data that isn't fully available until after this guide was written. We're not aware of a clear consensus projection yet for the 2027 IRA catch-up contribution specifically; expect it to move in step with whichever base limit applies.

What this means practically: if you're planning 2027 IRA contributions now, budget for $7,500 and treat any amount above that as a pleasant surprise rather than a guarantee — don't count on the higher figure until the IRS confirms it.

2027 HSA & HDHP Limits — Already Official

Unlike the limits above, these are confirmed — the IRS released them via Revenue Procedure 2026-24 on May 29, 2026:

HSA limits are calculated under a separate statutory formula (IRC §223, indexed to a different measurement period) than 401(k) and IRA limits, which is why the IRS can — and does — confirm them nearly a full year before the tax year begins. If you're doing HSA planning for 2027, these numbers are as solid as any tax figure gets before the year actually starts.

What to Do With These Numbers Before 401(k)/IRA Are Official

The HSA figures above are safe to plan around immediately — they're confirmed. For 401(k) and IRA, treat the projections as a reliable planning range, not a locked number:

• Payroll and benefits planning: if you're an employer or plan administrator budgeting 2027 payroll deductions, Milliman's projected figures are a reasonable working baseline, but final plan documents and payroll systems should be updated once the official IRS Notice publishes, typically in October or November.
• Personal contribution planning: if you're deciding how much to set aside per paycheck starting January 2027, planning around the lower end of the projected range (the current 2026 limit, or the more conservative projection) avoids under-withholding surprises if the final number lands lower than the optimistic estimate.
• Don't over-contribute based on a projection. If you set your 401(k) deferral percentage assuming a $25,500 limit and the IRS confirms a lower figure, you risk an excess contribution that has to be corrected by April 15 of the following year to avoid double taxation.
• Percentage-based deferrals adjust automatically, dollar-based ones don't. If your 401(k) deferral is set as a percentage of pay, most payroll systems will naturally cap you at whatever the confirmed limit turns out to be — you don't need to do anything before year-end. If you set a flat dollar amount per paycheck to hit a specific annual total, that number needs to be revisited once the real 2027 limit is confirmed, or you'll either leave contribution room on the table or need a mid-year correction.

One more practical wrinkle worth knowing about: because the 401(k) deferral limit and the IRA limit are calculated under different sections of the tax code with different rounding rules, it's entirely possible for the IRS to confirm one exactly as projected while the other lands differently — don't assume that because one number came in as expected, the other automatically did too. Check both independently once the official Notice is published.

We'll update this guide's 401(k) and IRA sections with confirmed figures the moment the IRS publishes its official 2027 Notice, expected October or November 2026.