A 401(k) is one of the most common employer-sponsored retirement arrangements in the United States—and one of the most important tax-planning tools available to many employees and business owners.

But there is no single “401(k) tax rule.” Traditional contributions, Roth contributions, employer matches, earnings, withdrawals, loans, hardship distributions, rollovers, Roth conversions, and required distributions can all receive different tax treatment.

Those decisions should be coordinated with broader tax planning rather than treating the retirement account only as an investment account.

What Is a 401(k)?

A 401(k) is an employer-sponsored retirement plan that allows eligible employees to contribute part of their compensation to individual accounts maintained within the employer's plan.

The IRS describes a 401(k) as a feature of a qualified profit-sharing plan that permits employees to contribute a portion of their wages to individual accounts.

Employee

You Contribute From Pay

Contributions are commonly made through payroll as traditional pre-tax deferrals, designated Roth contributions, or a combination when the plan permits.

Employer

Your Employer May Contribute

Employers may make matching, profit-sharing, safe-harbor, or other contributions depending on the terms of the retirement plan.

Investment

The Money Can Grow

Contributions are invested among funds or other investment options offered by the plan, allowing retirement assets to potentially compound over time.

How Traditional 401(k) Contributions Are Taxed

Traditional employee 401(k) salary deferrals are generally made on a pre-tax basis for federal income-tax purposes.

That means the amount deferred generally reduces the wages subject to current federal income tax.

Example: $75,000 salary with a $10,000 traditional 401(k) contribution

If an employee earns $75,000 and defers $10,000 into a traditional 401(k), federal wages subject to income tax may generally be reduced by the $10,000 deferral before considering other adjustments. The $10,000 has not escaped tax permanently—the income tax is generally deferred until the money is distributed.

Traditional elective deferrals generally do not avoid Social Security and Medicare payroll taxes in the same way they defer federal income tax.

In other words, reducing Box 1 taxable wages on Form W-2 does not necessarily mean Boxes 3 and 5 are reduced by the same amount.

How a Roth 401(k) Is Taxed

A designated Roth 401(k) essentially reverses the timing of the primary income-tax benefit.

Roth 401(k) contributions are generally made with after-tax dollars, meaning the employee does not receive the same current federal income-tax reduction from the contribution.

In exchange, qualified distributions can generally be received free from federal income tax when the applicable requirements are satisfied.

Traditional 401(k)	Roth 401(k)
Employee contribution generally reduces current wages subject to federal income tax.	Employee contribution is generally made after tax and does not reduce current federal taxable income.
Investment earnings generally grow tax-deferred.	Investment earnings can potentially be distributed tax-free when the qualified- distribution requirements are met.
Previously untaxed distributions are generally taxable as ordinary income.	Qualified Roth distributions are generally tax-free.
Generally subject to RMD rules.	Designated Roth 401(k) accounts are not subject to lifetime RMDs for the original account owner under current federal rules.

Choosing between traditional and Roth treatment is not simply about deciding which account is “better.”

Relevant considerations can include:

Your current marginal tax rate
Your expected future tax rate
Expected retirement income
Time available for investment growth
Future RMD exposure
Social Security taxation
Estate and beneficiary goals
Your overall mix of pre-tax and Roth assets

2026 401(k) Contribution Limits

Federal law limits how much employees and employers can contribute to retirement plans each year.

2026 Limit	Amount
Regular Employee Elective Deferral	$24,500
General Age 50+ Catch-Up	$8,000
Higher Catch-Up for Ages 60–63	$11,250 instead of the regular $8,000 catch-up when eligible.
Overall Defined-Contribution Limit	Generally $72,000 before applicable catch-up contributions, subject to compensation and other plan limitations.

The IRS publishes the current 401(k) and profit-sharing plan contribution limits .

A Major Roth Catch-Up Rule Begins in 2026

Beginning in 2026, certain higher-paid employees who make catch-up contributions generally must make those catch-up contributions on a Roth basis when the sponsoring plan offers the applicable Roth feature.

For 2026, the rule generally applies when the participant's prior-year wages from the employer sponsoring the plan exceeded $150,000, subject to the detailed statutory and plan rules.

NEW

This rule can change the current-year tax benefit of your catch-up contribution.

An employee who previously made a traditional pre-tax catch-up contribution may be required to make the 2026 catch-up contribution as Roth instead, meaning that portion generally will not reduce current federal taxable income.

See the IRS guidance on retirement-plan catch-up contributions .

How Employer Matching Contributions Are Taxed

Many employers encourage retirement-plan participation by matching a portion of employee contributions.

A plan might, for example, match a percentage of salary deferrals up to a stated percentage of compensation.

The employer match is part of your compensation package.

If your employer provides a match and you are otherwise financially able to contribute, failing to contribute enough to receive the available match can mean leaving an employer-provided retirement benefit unused.

Employer contributions also count toward the broader annual defined-contribution limits applicable to the plan.

Don't Forget About Vesting

Your own employee salary-deferral contributions are generally fully vested. Employer contributions, however, may be subject to a vesting schedule depending on the plan.

If employment ends before you become fully vested, some unvested employer contributions may be forfeited.

How Investment Growth Inside a 401(k) Is Taxed

One of the primary tax advantages of a retirement plan is that investment activity inside the plan generally does not create the same annual taxable events that similar investments might generate in an ordinary taxable brokerage account.

Interest, dividends, capital gains, and other investment growth generally remain inside the retirement account without creating current federal income tax merely because investments appreciated or generated earnings.

Traditional

Tax Deferred

Investment growth is generally not taxed annually. Previously untaxed amounts are generally taxable as ordinary income when later distributed.

Roth

Potentially Tax-Free

Growth within a designated Roth account can ultimately be distributed without federal income tax when the distribution satisfies the qualified-distribution requirements.

Important

Capital Gain Rates Usually Don't Carry Through

Traditional 401(k) distributions are generally taxed under retirement-distribution rules rather than giving investment gains inside the plan the same long-term capital-gain treatment they might receive in a taxable brokerage account.

How 401(k) Withdrawals Are Taxed

The tax treatment of a distribution depends heavily on the source of the money being withdrawn.

Traditional

Generally Taxable

Traditional pre-tax contributions and associated earnings are generally included in taxable income when distributed.

Roth

Potentially Tax-Free

Qualified distributions from a designated Roth 401(k) are generally received free from federal income tax.

Early Distribution

Possible Additional Tax

Taxable distributions received before age 59½ may also be subject to a 10% additional federal tax unless a specific statutory exception applies.

The IRS maintains a detailed list of exceptions to the additional tax on early retirement-plan distributions .

What Happens If You Take Money Out Before Age 59½?

An early distribution from a traditional 401(k) can potentially produce two separate federal tax consequences.

Regular Income Tax

Previously untaxed traditional 401(k) contributions and earnings are generally included in taxable income when distributed.

Potential 10% Additional Tax

When a taxable distribution occurs before age 59½, an additional 10% tax may apply unless a specific exception covers the distribution.

Do not assume an IRA withdrawal exception also applies to your 401(k).

The early-distribution exception rules for IRAs and employer retirement plans are not identical. For example, certain IRA exceptions involving first-time home purchases or higher-education expenses should not automatically be assumed to apply to an ordinary 401(k) withdrawal.

What Is a 401(k) Hardship Distribution?

Some 401(k) plans permit hardship distributions when a participant has an immediate and heavy financial need and the withdrawal meets applicable federal and plan requirements.

The IRS provides guidance on hardship distributions, early withdrawals, and retirement-plan loans .

A hardship withdrawal is not the same thing as a loan.

A hardship distribution removes money from the retirement account and generally is not repaid to the plan. A traditional hardship distribution is generally taxable and can also be subject to the 10% additional early-distribution tax unless another exception applies.

Hardship distributions also generally are not eligible for rollover treatment.

What About Borrowing From Your 401(k)?

Some—but not all—401(k) plans allow participant loans.

A properly structured and properly repaid retirement-plan loan is generally not treated as a taxable distribution when it satisfies the applicable federal and plan requirements.

The IRS explains retirement-plan loan requirements in detail.

LOAN

A 401(k) loan is not automatically “tax-free money.”

If the loan fails to satisfy the applicable repayment requirements, the outstanding amount can become a taxable plan distribution. Depending on age and the circumstances, the 10% additional early-distribution tax may also apply.

Employment changes can also complicate an outstanding loan, making it important to understand the plan's terms before borrowing.

How Do 401(k) Rollovers Affect Taxes?

Leaving an employer does not automatically mean an old 401(k) must be cashed out.

Depending on the plan and the taxpayer's circumstances, potential options may include:

Leaving the money in the former employer's plan
Rolling the account into a new employer's eligible plan
Rolling the money into an IRA
Converting eligible traditional amounts to Roth treatment
Taking a taxable distribution

Direct Rollovers

A properly completed direct rollover from an eligible traditional retirement plan to another eligible traditional retirement arrangement generally preserves the federal tax deferral.

60-Day Rollovers

When retirement money is paid directly to the participant instead of being sent to the receiving retirement account, additional withholding and rollover requirements can apply.

The IRS provides comprehensive information about rollovers of retirement-plan and IRA distributions .

→

A rollover is not the same thing as a Roth conversion.

Moving traditional pre-tax 401(k) money into another traditional tax-deferred account generally preserves the tax deferral. Moving traditional money into a Roth account can create current taxable income because the funds are changing from pre-tax to Roth treatment.

Required Minimum Distributions From a 401(k)

Traditional retirement accounts generally cannot remain tax-deferred indefinitely.

Under current federal rules, required minimum distributions generally begin at age 73 for taxpayers subject to the current starting-age rules.

The IRS maintains detailed required minimum distribution guidance .

The original article also referenced this external overview of required minimum distributions , which is retained here.

The Still-Working Exception

A participant in a current employer's qualified retirement plan may in some circumstances be permitted to delay RMDs from that employer's plan until retirement.

The exception generally does not apply to a participant who owns more than 5% of the employer sponsoring the plan, and the same postponement does not ordinarily apply to Traditional IRAs.

Roth 401(k)s Are Different

Under current federal law, designated Roth accounts within 401(k) and 403(b) plans are not subject to lifetime RMDs for the original account owner.

401(k) vs. Traditional IRA: How Do the Tax Rules Compare?

401(k)	Traditional IRA
Generally provided through an employer or through a one-participant 401(k) for an eligible business owner.	Individual retirement account generally established directly by the taxpayer.
2026 employee elective-deferral limit generally $24,500 before applicable catch-up contributions.	2026 IRA contribution limit generally $7,500, plus a $1,100 age-50+ catch-up.
Traditional salary deferrals generally reduce current federal taxable wages.	Traditional IRA contributions may or may not be deductible depending on filing status, income, and workplace retirement-plan coverage.
Employer contributions may be available.	No ordinary employer matching contribution to an individual's Traditional IRA.
Investment choices generally depend on the options offered by the plan.	Investment choices can often be substantially broader depending on the IRA custodian.
May permit participant loans if the plan contains a loan provision.	IRAs do not provide participant loans.
Certain current-employer plans may permit RMD postponement while the participant continues working, subject to applicable rules.	Traditional IRA RMD rules generally apply regardless of whether the taxpayer remains employed.

The IRS publishes current IRA contribution limits separately from employer retirement-plan limits.

Should You Prioritize a 401(k) or an IRA?

There is no universal answer—and the decision does not always have to be one account or the other.

Consider the Employer Match

If an employer offers a meaningful match, contributing enough to receive the available match may be an important first step.

Compare Investment Options and Fees

A strong employer plan can provide low-cost institutional investments. Other plans may offer limited investment choices or relatively high fees.

Consider the Current Tax Benefit

Traditional 401(k) contributions can provide a valuable current federal income-tax deferral, particularly during higher-income years.

Consider Roth Tax Diversification

Maintaining both pre-tax and Roth retirement assets can provide different tax characteristics and withdrawal options later in retirement.

The question does not always have to be “401(k) or IRA?”

Depending on income and eligibility, a taxpayer may contribute to an employer 401(k) and also fund an IRA. Separate rules determine whether a Traditional IRA contribution is deductible and whether a direct Roth IRA contribution is permitted.

401(k)s Can Be Powerful Tax-Planning Tools for Business Owners

Retirement plans are not only employee benefits. For business owners, a properly structured retirement plan can also become part of compensation planning, employee retention, tax reduction, and long-term wealth accumulation.

A business owner with no employees other than a spouse may potentially qualify for a one-participant or Solo 401(k) .

A qualifying owner may potentially contribute in more than one capacity—such as an employee elective deferral and an employer contribution—subject to compensation, plan, and annual contribution limits.

Biz

Business retirement planning should be coordinated with payroll and entity strategy.

For S corporations and other closely held companies, contribution calculations can interact with wages, reasonable compensation, employer deductions, payroll, cash flow, ownership, and overall tax planning.

Business owners should coordinate retirement contributions with their broader tax-planning strategy rather than viewing the plan in isolation.

Retirement Contributions Still Have to Fit Your Budget

Maximizing a retirement contribution may provide significant long-term savings and tax benefits—but it does not eliminate current cash-flow needs.

Before dramatically increasing payroll deferrals, consider:

Emergency reserves
High-interest debt
Mortgage and housing costs
Insurance needs
Monthly household obligations
Expected major purchases
Children and education costs
Business cash-flow needs
Other short- and long-term financial goals

A tax deduction is valuable only if the underlying financial decision makes sense.

Contributing aggressively to retirement while carrying unaffordable high-interest debt or leaving no emergency liquidity can create a financial problem even when the tax treatment is attractive.

If you need help building a spending framework first, review our article: How to Prepare a Budget .

For longer-term retirement cash-flow planning, also see: The Importance of Budgeting for Retirement .

Common 401(k) Tax Mistakes to Avoid

Assuming a traditional 401(k) contribution eliminates tax permanently rather than deferring it.
Assuming traditional salary deferrals eliminate Social Security and Medicare payroll taxes.
Taking an early withdrawal before determining whether the 10% additional tax applies.
Assuming IRA withdrawal exceptions automatically apply to an employer 401(k).
Cashing out an old 401(k) without considering rollover alternatives.
Using an indirect rollover without understanding mandatory withholding and the 60-day deadline.
Treating a hardship distribution as though it can simply be repaid later.
Borrowing from a 401(k) without understanding what can happen when employment ends.
Missing a required minimum distribution from a traditional retirement account.
Failing to review beneficiary designations after marriage, divorce, death, or another major life event.
Converting traditional retirement money to Roth treatment without planning for the taxable income created by the conversion.
Ignoring the 2026 Roth catch-up requirement when it applies.

Your 401(k) Should Be Part of a Larger Tax Strategy

A retirement account may look primarily like an investment account, but many of the decisions involving it can materially affect current and future taxable income.

Traditional versus Roth contributions affect when income is taxed. Roth conversions can create substantial taxable income in a chosen year. Business retirement contributions can affect company and owner tax planning. Retirement distributions can affect taxable income decades after the original contribution.

Retirement decisions can also interact with:

Marginal federal income-tax brackets
Capital gains
Social Security taxation
Medicare-related income thresholds
Required minimum distributions
Business compensation
Estimated tax payments
Charitable giving
Other deductions and credits

Azalea City Tax & Accounting

Retirement Contributions Can Be Part of Proactive Tax Planning

We help individuals and business owners evaluate traditional versus Roth contributions, retirement-plan limits, employer contributions, Roth conversions, distributions, entity structure, compensation, estimated taxes, and long-term tax consequences as part of a broader tax strategy.

Investment selection itself should be discussed with an appropriately licensed investment professional when individualized investment advice is needed.

Explore Tax Planning Services

A 401(k) Is About Tax Timing as Much as Retirement Saving

The tax advantages of a 401(k) can be substantial, but those advantages depend heavily on understanding when the tax is paid.

Traditional contributions generally provide a current income-tax deferral followed by taxable distributions later. Roth contributions generally provide no current income-tax deduction but can produce tax-free qualified distributions in retirement.

Employer contributions, catch-up contributions, loans, hardship withdrawals, rollovers, conversions, and RMDs add additional layers of tax rules.

The best approach is to treat retirement planning as part of your broader tax and financial picture rather than making contribution and distribution decisions in isolation.

Frequently Asked Questions

How much can I contribute to a 401(k) in 2026?

The regular employee elective-deferral limit for most 401(k) plans is $24,500 for 2026. Participants age 50 or older can generally make an additional $8,000 catch-up contribution. Participants who turn 60, 61, 62, or 63 during 2026 can generally use the higher $11,250 catch-up limit instead of the ordinary $8,000 catch-up, subject to plan eligibility and other applicable rules.

Do traditional 401(k) contributions reduce my taxable income?

Traditional employee salary deferrals generally reduce wages subject to federal income tax in the year of the contribution. They generally do not eliminate Social Security and Medicare payroll taxes. Federal income tax on previously untaxed traditional amounts is generally deferred until the money is distributed.

Do high-income employees have to make Roth catch-up contributions in 2026?

Under the new 2026 rule, participants making catch-up contributions generally must make those catch-up contributions on a Roth basis when their prior-year wages from the employer sponsoring the plan exceeded $150,000, subject to the applicable plan and statutory requirements.

What happens if I withdraw from my 401(k) before age 59½?

Previously untaxed traditional amounts are generally included in taxable income. A taxable distribution before age 59½ may also be subject to an additional 10% federal tax unless a specific statutory exception applies.

How do 401(k) rollovers affect taxes?

A properly completed rollover from a traditional 401(k) into another eligible traditional retirement arrangement can generally preserve tax deferral. Direct rollovers often simplify the process because funds move directly between retirement arrangements. Distributions paid directly to the participant can involve mandatory withholding and 60-day rollover requirements.

How do I decide between a traditional and Roth 401(k)?

Traditional contributions generally provide the income-tax benefit today and result in taxable distributions later. Roth contributions generally provide no current federal income-tax deduction but can produce tax-free qualified distributions later. The decision depends on current and expected future tax rates, income, retirement goals, time horizon, plan features, and broader tax strategy.

Do Roth 401(k)s have required minimum distributions?

Under current federal law, designated Roth accounts in 401(k) and 403(b) plans are not subject to required minimum distributions during the original account owner's lifetime. Beneficiaries can still be subject to distribution requirements after the owner's death.

Is a 401(k) loan taxable?

A properly structured 401(k) loan that satisfies the applicable federal and plan requirements generally is not treated as a taxable distribution. If the loan is not repaid according to the rules, the outstanding amount can become taxable and may also be subject to the additional 10% early-distribution tax depending on the circumstances.

Can I contribute to both a 401(k) and an IRA?

Yes. Participating in an employer 401(k) does not by itself prevent you from contributing to an IRA. Workplace-plan participation and income can affect whether a Traditional IRA contribution is deductible, while income limitations can affect eligibility to make a direct Roth IRA contribution.

At what age do traditional 401(k) RMDs begin?

Under current rules, RMDs generally begin at age 73 for individuals subject to the current starting-age rules. Certain participants may be able to delay distributions from their current employer's qualified plan until retirement if the applicable requirements are met and they are not a more-than-5% owner. Different rules can apply to IRAs, beneficiaries, and Roth accounts.

Can a business owner have a Solo 401(k)?

Potentially. A business owner with no common-law employees other than a spouse may qualify for a one-participant 401(k). Contribution limits, compensation, entity structure, employee-deferral rules, employer contributions, and annual filing requirements must still be considered.

Your Retirement Plan Can Affect Your Taxes Today—and for Decades to Come.

Azalea City Tax & Accounting can help evaluate traditional versus Roth treatment, retirement contributions, Solo 401(k)s, business retirement plans, Roth conversions, rollovers, distributions, RMDs, and other retirement decisions as part of a broader tax-planning strategy.

Call 251-380-6293 Request a Free Consultation

Important: This article provides general educational information and is not individualized tax, legal, retirement, investment, accounting, or financial advice. Retirement-plan rules depend on plan terms, age, compensation, employment status, contribution type, distribution type, prior-year wages, ownership, beneficiary status, and other circumstances. Contribution limits, tax rules, and required distribution rules can change. Investment selection and securities advice should be discussed with an appropriately licensed investment professional when individualized investment advice is needed.