In-Plan Roth Conversions: What High Earners Need to Know in 2026

Illustration of Roth conversion concept

The IRS’s latest rule for high‑income earners (those earning $150,000+ in Box 5) changes the game for catch‑up contributions. Starting in 2026, any catch‑up contribution you make to an IRA or Thrift Savings Plan will automatically go into a Roth vehicle.

Why the shift matters

Roth contributions are funded with after‑tax dollars, meaning qualified withdrawals are tax‑free. By forcing catch‑up money into Roth accounts, the IRS is essentially nudging high earners to pay tax now rather than later. This can be a boon if you expect your tax rate to rise, but a drawback if you anticipate lower rates in retirement.

In‑plan Roth conversions

Many 401(k) and 403(b) plans now allow “in‑plan Roth conversions,” letting you move pre‑tax balances into a Roth tranche within the same employer‑sponsored plan. With the new catch‑up rule, converting before you hit the $150k threshold can lock in a lower tax rate on the conversion.

Quick checklist

Using a retirement calculator can help you model the long‑term benefit of a Roth conversion versus staying in a traditional account.

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