Key Takeaways

  • Pre-tax 401(k) deferrals reduce current taxable income; Roth 401(k) provides tax-free qualified distributions
  • ADP test limits HCE deferrals based on NHCE participation: if NHCEs defer 2%, HCEs can defer 4%; if NHCEs defer 6%, HCEs can defer 8%
  • Safe harbor 401(k) requires either 3% non-elective contribution to all OR 100% match on first 3% plus 50% on next 2% of deferrals
  • QACA allows 3-month delayed safe harbor with 90-day auto-enrollment and 2-year cliff vesting on employer contributions
  • Plan loans limited to lesser of $50,000 or 50% of vested balance; hardship withdrawals require immediate and heavy financial need
Last updated: January 2026

401(k) Plan Features

A 401(k) plan is a Cash or Deferred Arrangement (CODA) that attaches to a profit sharing or stock bonus plan. It is the most prevalent type of employer-sponsored retirement plan today, predominantly funded through employee elective deferrals with optional employer matching contributions. Understanding 401(k) features, testing requirements, and distribution rules is critical for CFP exam success.

Salary Deferrals: Pre-Tax vs. Roth

Employees can defer compensation to a 401(k) on either a pre-tax or Roth (after-tax) basis, depending on plan design.

Pre-Tax Deferrals (Traditional 401(k))

FeatureDetails
Tax treatment at contributionReduces current taxable income
Tax treatment at distributionTaxed as ordinary income
Required minimum distributionsRequired beginning at age 73
Best forThose expecting lower tax rates in retirement

Roth 401(k) Deferrals

FeatureDetails
Tax treatment at contributionNo current tax deduction (after-tax)
Tax treatment at distributionTax-free if qualified
Qualified distribution requirements5 years from first Roth contribution AND age 59 1/2, death, or disability
Required minimum distributionsNo longer required (SECURE 2.0, effective 2024)
Best forThose expecting higher tax rates in retirement

Key Difference: Unlike Roth IRAs, Roth 401(k)s have no income limits for contributions. Any employee can make Roth 401(k) deferrals regardless of income.

Employer Matching Contributions

Employer matching contributions incentivize employee participation and increase overall savings rates. Common matching formulas include:

Common Matching Formulas

Formula TypeExampleEmployee Defers 6% on $100,000
Dollar-for-dollar up to X%100% match up to 3%$3,000 match
Partial match50% match up to 6%$3,000 match
Tiered match100% on first 3%, 50% on next 2%$4,000 match
DiscretionaryVaries year to yearBased on company decision

Vesting: Employee deferrals are always 100% vested immediately. Employer matching contributions may vest according to a schedule:

  • 2-6 year graded: 0%, 20%, 40%, 60%, 80%, 100%
  • 3-year cliff: 0% until year 3, then 100%

ADP/ACP Testing: Ensuring Nondiscrimination

Traditional 401(k) plans must pass nondiscrimination tests annually to ensure that Highly Compensated Employees (HCEs) do not disproportionately benefit compared to Non-Highly Compensated Employees (NHCEs).

Highly Compensated Employee (HCE) Definition (2025)

An employee is an HCE if:

  • >5% owner at any time during the current or prior year, OR
  • Compensation exceeded $160,000 in the prior year (with optional top 20% election)

The Actual Deferral Percentage (ADP) Test

The ADP test limits elective deferrals of HCEs based on the average deferral percentage of NHCEs.

ADP Test Formula:

If NHCE ADP is...Maximum HCE ADP is...
0% to 2%2 x NHCE ADP
2% to 8%NHCE ADP + 2%
Over 8%1.25 x NHCE ADP

ADP Test Examples:

NHCE Average DeferralMaximum HCE DeferralCalculation
1%2%1% x 2 = 2%
2%4%2% x 2 = 4%
3%5%3% + 2% = 5%
5%7%5% + 2% = 7%
8%10%8% + 2% = 10%
10%12.5%10% x 1.25 = 12.5%

The Actual Contribution Percentage (ACP) Test

The ACP test applies to:

  • Employee after-tax contributions (thrift contributions)
  • Employer matching contributions

The ACP test uses the same scale as the ADP test.

Correcting Failed ADP/ACP Tests

If a plan fails, corrections must be made by March 15 (2.5 months after plan year end) to avoid a 10% excise tax:

Correction MethodEffect
Corrective distributionsReturn excess contributions to HCEs (reduces HCE percentage)
RecharacterizationChange pre-tax to after-tax contributions (reduces ADP but increases ACP)
QNECs (Qualified Non-Elective Contributions)Employer contributes to all eligible NHCEs (increases NHCE percentage)
QMACs (Qualified Matching Contributions)Employer adds match only for deferring NHCEs (increases NHCE percentage)

Safe Harbor 401(k) Plans

Safe harbor 401(k) plans are exempt from ADP and ACP testing when specific contribution and notice requirements are met.

Safe Harbor Contribution Options

Safe Harbor TypeRequired Employer ContributionVesting
Non-Elective3% of compensation to ALL eligible employees100% immediate
Basic Match100% on first 3% + 50% on next 2% of deferrals100% immediate
Enhanced MatchAt least as generous as basic match100% immediate

Safe Harbor Basic Match Calculation:

Employee earning $100,000 who defers 5%:

  • Match on first 3%: 100% x $3,000 = $3,000
  • Match on next 2%: 50% x $2,000 = $1,000
  • Total match: $4,000 (4% of compensation)

Key Point: Safe harbor contributions must be 100% vested immediately. No graded or cliff vesting is permitted on safe harbor amounts.

Notice Requirement

Employers must provide eligible employees with written notice at least 30 days (and no more than 90 days) before the beginning of each plan year describing safe harbor contribution formula and other plan features.

QACA: Qualified Automatic Contribution Arrangement

A QACA combines automatic enrollment with safe harbor provisions for a modified ADP/ACP testing exemption.

QACA Requirements

FeatureRequirement
Automatic enrollmentDefault deferral of at least 3%, escalating annually by 1% to at least 10% (15% max cap)
Employer contributionBasic safe harbor match OR 3% non-elective
Vesting2-year cliff (not immediate)
WithdrawalsParticipants may withdraw auto-enrolled amounts within 90 days
Notice30-90 days before plan year

QACA Advantage: Unlike standard safe harbor, QACA allows 2-year cliff vesting on employer contributions rather than requiring immediate vesting.

Catch-Up Contributions

Participants age 50 or older by year-end may make additional catch-up contributions beyond the standard deferral limit.

2025 Catch-Up Limits

AgeStandard DeferralCatch-UpTotal
Under 50$23,500$0$23,500
50-59$23,500$7,500$31,000
60-63$23,500$11,250$34,750
64+$23,500$7,500$31,000

Catch-up contributions do NOT count toward the $70,000 annual additions limit.

In-Plan Roth Conversions

Many 401(k) plans permit in-plan Roth conversions, allowing participants to convert pre-tax amounts to Roth within the same plan.

In-Plan Roth Conversion Rules

FeatureDetails
AvailabilityPlan sponsor must elect to offer this feature
AmountNo dollar limit on conversion amount
Age restrictionCan be done at any age
Tax treatmentConverted amount is taxable as ordinary income in year of conversion
10% penaltyDoes not apply to conversions (even under age 59 1/2)
5-year ruleConverted amounts subject to their own 5-year holding period for penalty-free withdrawal

Strategic Use: In-plan conversions allow participants to convert at lower tax rates (e.g., after job loss or early retirement) while keeping funds in the plan's protected environment.

Hardship Withdrawals

Participants may take hardship withdrawals from their 401(k) if the plan permits and they have an immediate and heavy financial need.

Immediate and Heavy Financial Need (Safe Harbor Events)

Qualifying Event
Medical expenses for participant, spouse, or dependents
Purchase of primary residence (down payment)
Tuition and educational expenses for next 12 months
Prevention of eviction or mortgage foreclosure
Funeral and burial expenses
Repair of damage to principal residence

Hardship Withdrawal Rules

FeatureRequirement
AmountLimited to amount necessary to satisfy need
SourceMay include deferrals, but plan may restrict to contributions only (not earnings)
RepaymentCannot be repaid or rolled over
TaxesSubject to ordinary income tax
Penalty10% early withdrawal penalty applies unless exception met
Loan firstIRS no longer requires taking loans before hardship

SECURE 2.0 Emergency Withdrawals

SECURE 2.0 created new penalty-free withdrawal options:

TypeAmountPenalty
Emergency personal expenseUp to $1,000/year10% penalty waived
Domestic abuse victimsLesser of $10,000 or 50% vested balance10% penalty waived
Disaster reliefUp to $22,000 per disaster10% penalty waived

Plan Loans

401(k) plans may permit participants to borrow from their vested account balance.

Loan Limits

The maximum loan is the lesser of:

  • $50,000, OR
  • 50% of the participant's vested account balance

Reduced by: Highest outstanding loan balance in the prior 12 months.

Exception: If vested balance is under $20,000, the maximum loan is the lesser of:

  • $10,000, OR
  • The vested account balance

Loan Repayment Requirements

RequirementDetails
TermGenerally 5 years maximum
ExceptionUp to 15-30 years if used to purchase principal residence
PaymentsSubstantially level amortization, at least quarterly
Interest rateReasonable rate (typically prime + 1%)
TerminationLoan generally becomes due upon termination of employment
DefaultUnpaid balance becomes taxable distribution + 10% penalty if under 59 1/2

Loan Repayment After Termination (TCJA 2017)

If an employee terminates with an outstanding loan, they may rollover/repay the loan by the tax filing deadline (including extensions) to avoid the distribution being taxable.

On the CFP Exam

Expect questions on:

  • Calculating ADP/ACP test limits using the tiered formula
  • Understanding safe harbor contribution requirements (3% non-elective OR 100%/50% match)
  • Distinguishing pre-tax vs. Roth 401(k) taxation and distribution rules
  • Applying plan loan limits ($50,000 or 50% of vested balance)
  • Identifying hardship withdrawal qualifying events and consequences
Test Your Knowledge

A 401(k) plan's ADP test shows that NHCEs have an average deferral percentage of 4%. What is the maximum average deferral percentage permitted for HCEs?

A
B
C
D
Test Your Knowledge

Which statement about safe harbor 401(k) plans is CORRECT?

A
B
C
D
Test Your Knowledge

An employee with a vested 401(k) balance of $80,000 wants to take the maximum plan loan. She had no outstanding loans in the prior 12 months. What is the maximum she can borrow?

A
B
C
D