6.3 Voluntary After-Tax Contributions & Automatic Contribution Arrangements (ACA, EACA)

6.3 Voluntary After-Tax Contributions & Automatic Contribution Arrangements (ACA, EACA)

[!NOTE] Overcoming Inertia & Maximizing Savings: Plan design in modern defined contribution administration balances two critical policy objectives: expanding coverage among rank-and-file employees through behavioral "nudges," and providing high-income participants with tax-efficient capital accumulation. Internal Revenue Code (IRC) provisions govern both ends of this spectrum. On one end, Voluntary After-Tax Employee Contributions permit participants who have exhausted statutory elective deferral ceilings to continue saving up to the full annual additions limit under IRC §415(c). On the other end, Automatic Contribution Arrangements (codified across IRC §414(w), §401(k)(13), and SECURE 2.0 §101) utilize defaults to automatically enroll eligible employees and systematically escalate savings rates.

Qualified 401(k) Administrators must master the mechanical rules governing after-tax nondiscrimination testing (the ACP test under IRC §401(m)), in-plan Roth conversion strategies, statutory automatic enrollment safe harbors, and the mandatory auto-enrollment landscape established by SECURE 2.0.

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Voluntary After-Tax Contributions: Mechanics, Limits, and ACP Testing

Voluntary after-tax employee contributions are contributions made by an employee to a qualified plan on an after-tax basis that are not designated Roth contributions under IRC §402A.

The Critical Distinction: Voluntary After-Tax vs. Designated Roth 401(k)

Although both contribution types are funded from post-tax wages (subject to current federal, state, and FICA taxes), their long-term tax treatment diverges sharply:

Impact on Statutory Limits: IRC §402(g) vs. IRC §415(c)

Because voluntary after-tax contributions are authorized under general profit-sharing rules rather than as a cash or deferred arrangement under §401(k), they are not subject to the IRC §402(g) annual elective deferral ceiling ($24,500 in 2026). However, they are treated as annual additions under IRC §415(c), which caps total contributions to the lesser of:

1. 100% of participant compensation, OR
2. $72,000 (for 2026) ($69,000 in 2024; $70,000 in 2025).

ACP Nondiscrimination Testing Under IRC §401(m)

Under IRC §401(m)(2), voluntary after-tax contributions must be tested annually under the Actual Contribution Percentage (ACP) test, combined with any employer matching contributions. Because after-tax contributions are disproportionately utilized by Highly Compensated Employees (HCEs), plans that permit voluntary after-tax contributions frequently fail the ACP test unless rank-and-file Non-Highly Compensated Employees (NHCEs) also contribute substantial after-tax dollars, or unless the plan adopts special restrictive caps for HCEs.

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The "Mega-Backdoor Roth" Rollover Strategy

The statutory intersection of voluntary after-tax contributions, IRC §415(c), and in-plan Roth conversions gave rise to the advanced wealth-accumulation technique known in the retirement industry as the "Mega-Backdoor Roth."

+-----------------------------------------------------------------------------------------+
|                   THE 2026 MEGA-BACKDOOR ROTH ALLOCATION ARCHITECTURE                   |
+-----------------------------------------------------------------------------------------+
|                                                                                         |
|  STEP 1: Maximize Standard §402(g) Deferrals:                                           |
|          • Elect $24,500 in Pre-Tax or Designated Roth 401(k) Deferrals                 |
|                                                                                         |
|  STEP 2: Factor in Employer Contributions:                                              |
|          • Sponsoring Employer contributes $10,500 in Matching / Profit-Sharing         |
|          • Subtotal Allocated: $24,500 + $10,500 = $35,000                              |
|                                                                                         |
|  STEP 3: Fill Remaining IRC §415(c) Headroom with After-Tax Dollars:                    |
|          • 2026 §415(c) Limit: $72,000                                                  |
|          • Available After-Tax Space: $72,000 - $35,000 = $37,000                       |
|          • Participant contributes $37,000 in Voluntary After-Tax Contributions         |
|                                                                                         |
|  STEP 4: Immediate In-Plan Roth Rollover (IRR) / Split Rollover:                        |
|          • Immediately convert the $37,000 After-Tax Basis into Designated Roth         |
|          • Result: $37,000 shifted to Roth without tax; all future growth 100% TAX-FREE!|
+-----------------------------------------------------------------------------------------+

IRS Notice 2014-54: Split Rollovers

Prior to 2014, plan distributions containing both after-tax basis and pre-tax earnings were subject to strict pro-rata distribution rules, making it difficult to separate taxable earnings from non-taxable basis. Under IRS Notice 2014-54, the IRS permitted participants taking a simultaneous distribution from a qualified plan to direct:

• The after-tax basis directly to a Roth IRA (with zero income tax owed);
• The pre-tax earnings directly to a Traditional IRA (preserving tax deferral).

Alternatively, participants may execute an immediate In-Plan Roth Rollover (IRR) under IRC §402A(c)(4), converting the after-tax basis to a designated Roth 401(k) account before any substantial earnings accumulate.

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The Spectrum of Automatic Contribution Arrangements

To combat the behavioral tendency of eligible employees to procrastinate or fail to enroll in company retirement plans, Congress passed the Pension Protection Act of 2006 (PPA 2006), creating statutory frameworks for automatic enrollment. Under ERISA §514(e), federal law explicitly preempts state wage-withholding and wage-garnishment laws, allowing employers to automatically withhold salary for retirement contributions without obtaining a prior signed paycheck deduction authorization, provided statutory notice rules are met.

Modern retirement plans utilize three distinct generations of automatic enrollment:

                                THE AUTOMATIC ENROLLMENT CONTINUUM
                                                │
      ┌─────────────────────────────────────────┼─────────────────────────────────────────┐
      ▼                                         ▼                                         ▼
   [ ACA ]                                   [ EACA ]                                  [ QACA ]
Basic Automatic Arrangement               Eligible Automatic Arrangement            Qualified Automatic Arrangement
IRC §401(k) / Treas. Reg. §1.401(k)-1     IRC §414(w)                               IRC §401(k)(13) / §401(m)(12)
• Default enrollment                      • Uniformity requirement                  • Safe Harbor: ADP/ACP exempt
• Standard ADP/ACP testing                • 90-day permissive withdrawal            • Mandatory auto-escalation (3%->6%+)
• 2.5-month correction deadline           • 6-month §4979 testing window            • 3.5% match or 3% nonelective
• No permissive withdrawal                • Annual notice (30-90 days)              • Up to 2-year cliff vesting

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1. Automatic Contribution Arrangement (ACA)

A basic Automatic Contribution Arrangement (ACA) is an arrangement under which an eligible employee is treated as having elected to make elective deferrals at a default percentage specified in the plan document, unless the employee affirmatively elects a different percentage or opts out entirely.

• Standard Compliance: An ACA provides no special testing relief. The plan remains fully subject to annual ADP testing under IRC §401(k)(3) and ACP testing under IRC §401(m)(2).
• Correction Timeline: The plan is subject to the standard statutory deadline of 2.5 months following the plan year-end (March 15 for calendar-year plans) to refund excess contributions; otherwise, the employer is hit with a 10% excise tax under IRC §4979.
• No Permissive Withdrawal: Employees do not have a statutory right to undo default deferrals.

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2. Eligible Automatic Contribution Arrangement (EACA) - IRC §414(w)

An Eligible Automatic Contribution Arrangement (EACA) provides plan sponsors with enhanced operational flexibility and participant protections under IRC §414(w) and Treas. Reg. §1.414(w)-1.

Key Statutory Requirements for EACA Status:

1. Uniform Default Percentage: The plan must apply a uniform default percentage of compensation to all automatically enrolled participants. The default rate may be fixed (e.g., 5%) or incorporate an automatic annual escalation schedule.
2. The Annual Notice Mandate: The plan administrator must provide written notice to each covered employee within a "reasonable period"—statutorily defined as at least 30 days and not more than 90 days before the beginning of each plan year (or on the date of hire for new employees). The notice must clearly explain the default percentage, the employee's right to opt out or change rates, and how investments will be directed (typically to a Qualified Default Investment Alternative / QDIA).

The 90-Day Permissive Withdrawal Right (IRC §414(w))

An EACA plan may include a permissive withdrawal provision. Under this rule:

• An automatically enrolled employee has the right to elect to withdraw all default contributions made to the plan within not less than 30 days and not more than 90 days after the date of the first default payroll deduction.
• Tax Treatment: Withdrawn contributions are includible in the employee's gross income in the taxable year in which the distribution is paid (reported on Form 1099-R).
• Penalty Exemption: The distribution is completely exempt from the IRC §72(t) 10% early distribution excise tax.
• Mandatory Match Forfeiture: Any employer matching contributions allocated on account of the withdrawn default deferrals must be forfeited under IRC §414(w)(5). The employee cannot keep matching dollars on withdrawn contributions.

The Extended 6-Month Correction Window (IRC §4979(f)(1))

Under general rules, if a plan fails the ADP or ACP test, the employer must distribute corrective refunds within 2.5 months after the close of the plan year (March 15 for calendar-year plans) to avoid paying a 10% employer excise tax on the excess contributions under IRC §4979. However:

• Under IRC §4979(f)(1), if a plan maintains an EACA covering all eligible employees, the deadline to distribute corrective refunds without incurring the 10% excise tax is extended from 2.5 months to 6 months following the plan year-end (June 30 for calendar-year plans)!
• This extended window gives administrators crucial additional time to gather complete census data, perform testing, and calculate allocable earnings.

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3. Qualified Automatic Contribution Arrangement (QACA) - IRC §401(k)(13)

A Qualified Automatic Contribution Arrangement (QACA) is a specialized safe-harbor plan design established by PPA 2006 under IRC §401(k)(13) and IRC §401(m)(12). By incorporating automatic enrollment into a safe harbor structure, a QACA allows a plan to bypass annual ADP and ACP testing entirely.

Safe Harbor Exemptions

A properly administered QACA automatically satisfies:

1. The ADP test under IRC §401(k)(3);
2. The ACP test under IRC §401(m)(2) (provided matching conditions are satisfied); and
3. The Top-Heavy rules under IRC §416(g)(4)(H) (if the plan consists solely of safe harbor contributions and deferrals).

Mandatory Minimum Default Escalation Schedule

Under IRC §401(k)(13)(C)(iii), a QACA must implement a statutory minimum default deferral schedule that automatically escalates participant deferrals:

+-----------------------------------------------------------------------------------------+
|                   QACA STATUTORY MINIMUM DEFAULT ESCALATION SCHEDULE                    |
+-----------------------------------------------------------------------------------------+
|  Plan Participation Period                     Statutory Minimum Default Deferral Rate  |
|  ------------------------------------------    ---------------------------------------  |
|  Initial Period (Hire Year through End of       At least 3% of compensation              |
|  Following Plan Year)                          (Plan can select initial rate up to 10%) |
|  Second Full Plan Year                         At least 4% of compensation              |
|  Third Full Plan Year                          At least 5% of compensation              |
|  Fourth Full Plan Year and Subsequent Years    At least 6% of compensation              |
|  Statutory Ceiling Cap                         Pre-SECURE: 10% / Post-SECURE: 15% cap   |
+-----------------------------------------------------------------------------------------+

Mandatory Employer Contributions for QACAs

To maintain QACA safe harbor status, the employer must provide one of two statutory contribution formulas:

Option A: The QACA Safe Harbor Matching Formula

The employer must match:

• 100% of elective deferrals up to the first 1% of compensation, PLUS
• 50% of elective deferrals between 1% and 6% of compensation.

$\text{Maximum QACA Match} = (1.00 \times 1\%) + (0.50 \times 5\%) = 1.0\% + 2.5\% = \mathbf{3.5\%}$

[!IMPORTANT] QACA Match vs. Traditional Safe Harbor Basic Match: A classic ASPPA QKA exam comparison is the difference between traditional safe harbor and QACA matching formulas:

• Traditional Safe Harbor Basic Match (IRC §401(k)(12)): 100% match on first 3% of pay, plus 50% match on next 2% of pay = 4.0% maximum match on 5% deferred.
• QACA Safe Harbor Match (IRC §401(k)(13)): 100% match on first 1% of pay, plus 50% match on next 5% of pay = 3.5% maximum match on 6% deferred.
• A QACA match requires less employer funding (3.5% vs. 4.0%) while incentivizing a higher employee deferral rate (6% vs. 5%)!

Option B: The QACA Safe Harbor Nonelective Formula

The employer must contribute at least 3% of compensation to all eligible Non-Highly Compensated Employees (NHCEs), regardless of whether they make elective deferrals.

Permissible Vesting: The Two-Year Cliff Rule

In a traditional safe harbor 401(k) plan, employer safe harbor matching and nonelective contributions must be 100% immediately vested at all times (IRC §401(k)(12)(E)).

In contrast, under IRC §401(k)(13)(D), an employer maintaining a QACA is permitted to subject safe harbor matching or nonelective contributions to a two-year cliff vesting schedule:

• 0% vested for less than 2 Years of Service;
• 100% vested upon completing 2 Years of Service.

This 2-year vesting allowance makes QACA designs immensely attractive to high-turnover employers (e.g., retail, hospitality, manufacturing) who wish to enjoy safe harbor testing exemptions while forfeiting contributions made to short-term workers who leave before completing two years.

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Master Comparative Matrix: ACA vs. EACA vs. QACA

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SECURE 2.0 §101: Mandatory Automatic Enrollment for New Plans

Prior to the SECURE 2.0 Act of 2022, adopting automatic contribution arrangements was entirely voluntary. Section 101 of SECURE 2.0 enacted IRC §414A, transforming automatic enrollment from a voluntary design feature into a mandatory statutory requirement for newly established plans.

Scope and Effective Date

• Effective Date: Applies to plan years beginning after December 31, 2024 (effective for 2025 and subsequent plan years).
• Covered Plans: Applies to all new 401(k) and 403(b) plans established on or after December 29, 2022 (the date of enactment of SECURE 2.0).

Mandatory Contribution and Escalation Parameters

Plans subject to IRC §414A must operate as an Eligible Automatic Contribution Arrangement (EACA) under IRC §414(w) and satisfy strict automatic escalation parameters:

1. Initial Default Deferral Rate: Must be set between at least 3% and not more than 10% of compensation.
2. Mandatory Automatic Escalation: The plan must automatically escalate the deferral percentage by 1% each year on the first day of each plan year, until the deferral rate reaches at least 10% (and no more than 15%).
3. Permissive Withdrawal: Must provide participants with the 90-day permissive withdrawal right under IRC §414(w).

Statutory Exemptions from Mandatory Automatic Enrollment

Under IRC §414A(c), Congress carved out five specific categories of plans exempt from mandatory automatic enrollment:

1. Grandfathered Plans: Any 401(k) or 403(b) plan established before December 29, 2022.
2. Small Businesses: Employers that normally employ 10 or fewer employees.
3. New / Startup Businesses: Sponsoring employers that have been in existence for less than three years (measured from the date the business began operations).
4. Governmental and Church Plans: All public-sector governmental plans (IRC §414(d)) and church plans (IRC §414(e)).
5. SIMPLE 401(k) Plans: Plans established under IRC §401(k)(11).

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Practical Worked Scenario: EACA Permissive Withdrawal Accounting

To understand how an EACA permissive withdrawal operates in day-to-day TPA recordkeeping, consider the following administrative case:

The Setup

• Plan Design: Calendar-year 401(k) plan with an EACA feature, 90-day permissive withdrawal, and a discretionary 50% match on deferrals up to 6% of pay.
• Employee: Brenda is hired on January 15, 2026. She receives the required EACA notice during onboarding.
• First Payroll: Brenda's first paycheck is issued on January 31, 2026. The employer automatically deducts a 5% default deferral ($250) and credits a 50% matching contribution ($125).
• Second & Third Payrolls: In February and March 2026, Brenda receives 4 more bi-weekly paychecks, resulting in cumulative default deferrals of $1,250 and cumulative matching contributions of $625.
• The Election: On April 5, 2026 (65 days after her first payroll deduction), Brenda files a formal election requesting a 100% permissive withdrawal of all default contributions under IRC §414(w).

TPA Administrative Accounting:

1. Evaluate Timing: The request was filed within the statutory 90-day window (65 days < 90 days). Brenda is fully entitled to the permissive withdrawal.
2. Calculate Distribution Amount: Brenda's total default deferrals equal $1,250. Allocable earnings credited to her deferral account equal $40. The total distribution paid to Brenda is $1,290.
3. Tax and Reporting Treatment: The $1,290 distribution is includible in Brenda's gross income for 2026. It is reported on Form 1099-R. Under IRC §414(w)(1)(B), the distribution is 100% exempt from the IRC §72(t) 10% early distribution penalty, even though Brenda is only 28 years old.
4. Handling the Employer Match: The employer match of $625 (plus its $20 allocable earnings = $645) cannot be distributed to Brenda. Pursuant to IRC §414(w)(5), the entire $645 matching balance is forfeited and transferred to the plan's forfeiture suspense account, to be used to defray plan administrative expenses or offset future employer contributions.

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Common ASPPA QKA Exam Traps

• Exam Trap 1: QACA Vesting vs. Traditional Safe Harbor Vesting: Exam questions frequently test whether safe harbor contributions can be subject to vesting. Traditional safe harbor matching and nonelective contributions must be 100% immediately vested. A QACA safe harbor, however, permits a 2-year cliff vesting schedule (100% after 2 Years of Service). Confusing these two rules is a major point-loser.
• Exam Trap 2: The EACA 6-Month Correction Window Condition: Many candidates believe any plan with an automatic enrollment feature gets the extended 6-month deadline (June 30) to correct failed ADP tests without the 10% excise tax under §4979. To qualify for the 6-month window under IRC §4979(f)(1), the plan must be an EACA that covers all eligible employees in the plan, not merely newly eligible workers.
• Exam Trap 3: Permissive Withdrawal Matching Forfeitures: A scenario may ask what happens to matching contributions when an employee executes an EACA 90-day permissive withdrawal. Novice administrators assume the match is paid out or remains vested. Under IRC §414(w)(5), matching contributions on withdrawn default deferrals must always be forfeited.
• Exam Trap 4: Voluntary After-Tax Rollovers to Roth: Candidates sometimes assume after-tax earnings can roll into a Roth IRA tax-free. Under IRS Notice 2014-54, only the after-tax contribution basis can roll into a Roth IRA tax-free; any accumulated earnings must either be taxed upon conversion or rolled over into a Traditional IRA to preserve tax deferral.