Can You Contribute to a 401(k) After Retirement?

You can keep contributing to a 401(k) after retirement as long as you have earned income from a job and your employer’s plan lets you participate. There is no upper age limit. If you take a part-time role, consult on the side, or start a second career, you can defer up to $24,500 of your own pay into a 401(k) in 2026, with more room if you’re 50 or older. What you can’t do is fund a 401(k) with Social Security checks, pension income, or investment returns. No paycheck, no contribution.

Earned Income Is the Threshold Requirement

A 401(k) contribution has to come from taxable compensation you receive for work: wages, salary, tips, bonuses, or self-employment income. Social Security benefits, pension payments, dividends, interest, and rental income don’t qualify. If those passive streams are your only income, you can’t make new 401(k) contributions no matter how large your savings.¹

Your contributions for the year also can’t exceed the compensation you actually earned that year. Pull in $15,000 from a part-time job and your maximum elective deferral is $15,000, even though the IRS limit sits higher. The plan itself can only count up to $360,000 of your annual compensation when calculating contributions for 2026.²

Age Doesn’t Cap You, but Plan Eligibility Might

Federal law puts no age ceiling on 401(k) contributions. A 78-year-old employee has the same deferral rights as a 28-year-old, provided both work for a company that offers a plan. Before the SECURE Act of 2019, Traditional IRA contributions were cut off at age 70½, which created some lingering confusion about whether similar limits touched 401(k)s. They didn’t then and they don’t now.³

The practical barrier is the plan’s own eligibility rules. Many employer plans require at least 1,000 hours of work per year, roughly 20 hours a week, before you can join. If you’re working only a few hours a week in retirement, you may not qualify.⁴

The Long-Term Part-Time Rule

SECURE 2.0 created a path for people who never hit 1,000 hours. Starting in 2025, if you work at least 500 hours a year for two consecutive years and are at least 21, your employer’s 401(k) plan has to let you make elective deferrals. Employers aren’t required to match contributions for these part-time participants, so the benefit is limited to tax-deferred savings on the money you put in yourself.⁴

Coming Back to a Former Employer

If you retire and then return to work for the same company, you can rejoin the plan and keep accruing benefits. There’s no new waiting period if you already met the eligibility requirements before you left.⁴

2026 Contribution Limits

The IRS adjusts 401(k) contribution ceilings for inflation each year. For 2026:

The enhanced catch-up between ages 60 and 63 is one of the most useful SECURE 2.0 provisions for people who work past traditional retirement age. A 61-year-old with part-time earnings of at least $35,750 could shelter every dollar of that income through elective deferrals alone. At 64, you go back to the standard $8,000 catch-up.

Mandatory Roth Catch-Up for High Earners

Starting in 2026, if your W-2 wages from the employer sponsoring the plan were more than $145,000 the prior year (indexed for inflation), all of your catch-up contributions have to go into a Roth account within the plan. You still get to make the catch-up, but you lose the upfront tax deduction on that portion; qualified withdrawals later come out tax-free. For 2026 contributions, the test looks at your 2025 wages.³

Under the threshold, you can still choose between pre-tax and Roth catch-up dollars if the plan offers a Roth option. The rule touches only the catch-up amount. Your regular deferrals up to $24,500 aren’t affected.

Self-Employed? Open a Solo 401(k)

Retirees often skip traditional employment and take on freelance projects, consulting work, or a small business. That 1099 income counts as earned income and can support 401(k) contributions, but you’ll need your own plan. A solo 401(k), also called a one-participant 401(k), lets you contribute as both the employee and the employer.⁶

On the employee side, you can defer up to $24,500 plus whichever catch-up amount applies to your age. On the employer side, you can add up to 25% of your compensation. For a self-employed person, “compensation” means net self-employment earnings after subtracting half your self-employment tax and the plan contribution itself, a circular calculation the IRS walks through with rate tables in Publication 560.⁷

All contributions together still can’t top the $72,000 annual addition limit before catch-up. For a retiree with meaningful consulting income, the dual employee-and-employer structure of a solo 401(k) shelters more earnings than a SEP-IRA or SIMPLE plan would.

How New Contributions Interact with RMDs

Most retirement account holders have to start taking required minimum distributions at age 73. Under SECURE 2.0, that threshold rises to 75 for people born in 1960 or later, but the change doesn’t take effect until 2033.⁸

If you’re still working for the employer that sponsors your 401(k), you can delay RMDs from that specific plan until April 1 of the year after you actually retire. This still-working exception is one of the strongest reasons to keep contributing past your RMD age: you’re adding new money and deferring tax on the existing balance at the same time.⁹

The exception covers only the plan at your current employer. Balances in a former employer’s plan or in a Traditional IRA still require distributions on the normal schedule. If your current plan accepts incoming rollovers, you can consolidate old 401(k) balances into it and bring the entire amount under the still-working shelter. Not every plan allows this, so ask the plan administrator.

The 5% Owner Exception

If you own more than 5% of the company sponsoring the plan, the still-working exception doesn’t apply. You must begin RMDs at age 73 (or 75 once that takes effect) even if you keep working. Ownership is determined through attribution rules, so shares held by your spouse or certain family members can be counted as yours.⁹

Watch the Social Security Earnings Test

Working after retirement can also reduce your Social Security benefits temporarily. If you claimed Social Security before reaching full retirement age, the earnings test cuts your benefit by $1 for every $2 you earn above $24,480 in 2026.¹⁰

In the calendar year you reach full retirement age, the formula loosens: $1 withheld for every $3 above $65,160, counting only earnings before the month you hit full retirement age.¹¹

Withheld benefits aren’t lost. Once you reach full retirement age, Social Security recalculates your monthly benefit upward to account for the months of reduction. One trap: pre-tax 401(k) deferrals do not reduce the wages that count toward the earnings test. Social Security looks at gross pay, not the taxable amount after your deferral.

1
Internal Revenue Service. Retirement Topics – Contributions
2
IRS.gov. 2026 Amounts Relating to Retirement Plans and IRAs, as Adjusted for Changes in Cost-of-Living (Notice 2025-67)
3
Internal Revenue Service. Treasury, IRS Issue Final Regulations on New Roth Catch-Up Rule, Other SECURE 2.0 Act Provisions
4
U.S. Department of Labor. FAQs About Retirement Plans and ERISA
5
Internal Revenue Service. 401(k) Limit Increases to $24,500 for 2026, IRA Limit Increases to $7,500
6
Internal Revenue Service. One-Participant 401(k) Plans
7
Internal Revenue Service. Self-Employed Individuals – Calculating Your Own Retirement Plan Contribution and Deduction
8
Internal Revenue Service. Retirement Plan and IRA Required Minimum Distributions FAQs
9
Internal Revenue Service. RMD Comparison Chart (IRAs vs. Defined Contribution Plans)
10
Social Security Administration. Receiving Benefits While Working
11
Social Security Administration. Determination of Exempt Amounts