A defined contribution plan is a retirement plan that defines what goes into an individual account for an employee rather than what comes out of it at retirement. Contributions are specified, the account is invested, and the benefit is whatever the account is worth when the employee takes it. A defined benefit plan works the other way around: it specifies the benefit and leaves the funding to be worked out.

That single difference drives almost everything else, including who carries the investment risk, how the annual limits are measured, whether an actuary is involved, and what the employer files each year. The 401(k) plan is the most widely recognized plan in the defined contribution category, but the category is broader than that, and the rules described below apply across it.

What follows sets out what the Internal Revenue Code, the IRS, and the Department of Labor provide on each point, with the 2026 dollar figures as published by the IRS. Where an answer depends on a plan’s own document or on facts specific to an employer, the text says so. It is general information about how these plans work rather than a determination about any particular plan or employer.

What a Defined Contribution Plan Is

The defining feature is the individual account. Each participant has an account under the plan, contributions are allocated to it, investment gains and losses are credited to it, and the participant’s benefit is based on that account balance. The IRS describes the category, alongside the other plan structures available to employers, on its page covering types of retirement plans.

Where the money in the account comes from

Depending on the plan document, an account can receive several distinct kinds of contribution:

• elective deferrals, meaning amounts a participant elects to have withheld from pay, made either on a pre-tax basis or as designated Roth contributions where the plan permits them
• employer matching contributions, which are conditioned on the participant contributing
• employer nonelective contributions, including profit sharing allocations and safe harbor nonelective contributions, which are not conditioned on the participant contributing
• after-tax contributions that are neither pre-tax deferrals nor designated Roth contributions, where the plan provides for them
• amounts rolled in from another eligible plan or from an individual retirement arrangement, where the plan accepts rollovers
• forfeitures reallocated from the unvested accounts of employees who left, where the plan document directs that use

Which of these a given plan actually has is a function of its plan document. The categories matter because the annual limits described further down treat them differently.

How the account is invested

In most defined contribution plans the participant directs the investment of their own account from a menu the plan’s fiduciaries select and monitor. Selecting and monitoring that menu is itself a fiduciary act under ERISA, and it remains a fiduciary act whether or not participants do the choosing.

Two provisions shape how the arrangement is usually built. ERISA section 404(c) provides that where a plan permits participants to exercise control over the assets in their accounts and meets the conditions in the Department of Labor’s regulation, a fiduciary is not liable for the results of the investment decisions the participant makes. The relief does not extend to the selection and monitoring of the menu the participant chooses from. Separately, the qualified default investment alternative regulation at 29 CFR 2550.404c-5 provides conditional relief where contributions are invested on a participant’s behalf because that participant did not make an election, which is the mechanism that makes automatic enrollment workable.

Not every defined contribution plan is participant-directed. Where the plan’s fiduciaries direct the investment of plan assets as a whole, or where the plan holds an asset without a public market, the fiduciary analysis and the valuation work are different, and neither of those situations changes the plan’s category.

What the employer commits to, and what it does not

In a defined contribution plan the employer’s commitment runs to the contribution formula written in the plan document, not to an ending account value. The plan does not promise a particular balance at retirement, and investment performance changes the benefit rather than the employer’s obligation.

That does not make the arrangement obligation-free. The employer remains responsible for operating the plan according to its terms and the Code, for the fiduciary duties ERISA imposes on the people who run it and select its investments, and for the annual reporting, testing, and disclosure the plan is subject to. The Department of Labor sets out the fiduciary framework in Meeting Your Fiduciary Responsibilities.

Defined Contribution vs. Defined Benefit: The Differences That Matter

Both are qualified retirement plans and both are subject to ERISA and to the Internal Revenue Code. The distinction is structural, and it is easiest to see in a direct comparison.

How the promise is written

A defined benefit plan states a benefit, for example a monthly amount at a stated retirement age calculated from average pay and years of service. Working out what has to be contributed to deliver that benefit is an actuarial exercise performed annually. A defined contribution plan states a contribution, for example a percentage of pay or a match on deferrals, and the account balance follows from the contributions and the investment results.

Who carries the investment risk

This is the practical consequence of the structural difference. In a defined contribution plan, investment results change the participant’s benefit. In a defined benefit plan, the promised benefit does not change with investment results, so investment shortfalls change what the employer has to contribute. Neither structure removes risk from the arrangement; they place it differently.

How the annual limits are measured

The two structures are limited at opposite ends. Code section 415(c) limits annual additions to a participant’s account in a defined contribution plan, which is $72,000 for 2026. Code section 415(b) limits the annual benefit payable from a defined benefit plan, which is $290,000 for 2026. Both figures are published in the IRS cost-of-living table and come from Notice 2025-67.

What happens when an employee leaves

The structures behave differently on separation. A defined contribution account is a balance, so a departing participant’s vested account can generally be paid out or rolled over to another eligible plan or an individual retirement arrangement, subject to the plan’s terms. A defined benefit plan generally holds a promise payable at a future retirement date, and while a lump sum may be available where the plan provides for one, the default form is a benefit that begins later. Unvested employer amounts are forfeited under either structure according to the plan’s vesting schedule.

How predictable the employer’s cost is

In a defined contribution plan the employer’s annual cost is a function of the formula in the plan document and the payroll it applies to, and in a design with discretionary contributions the employer decides the amount each year within the document’s terms. In a defined benefit plan the annual cost is the funding requirement the actuary determines, which moves with investment results, interest rates, and demographic assumptions. This is the same difference in risk placement described above, expressed as a budgeting question rather than a benefit question.

Arrangements that use both structures

The two categories are not mutually exclusive at the employer level. An employer can sponsor both a defined contribution plan and a defined benefit plan, in which case the limits apply separately to each. A cash balance plan is a defined benefit plan that expresses the benefit as a hypothetical account balance with stated pay credits and interest credits, which makes it look like a defined contribution plan from the participant’s side while remaining a defined benefit plan for funding, actuarial, and limit purposes. Which structure or combination fits a particular employer is a design question for that employer and its advisors, and it is the subject of establishing a new plan or changing an existing one.

The Types of Defined Contribution Plan

Several distinct plan types sit inside the category. They differ in who can sponsor them, whether employees can defer from pay, what the employer has to contribute, and which testing applies.

401(k) and safe harbor 401(k) plans

A 401(k) plan permits participants to elect deferrals from pay, and the plan document determines whether the employer matches them, contributes without regard to them, or does both. A standard 401(k) plan is subject to the nondiscrimination tests described further down. A safe harbor design substitutes prescribed employer contributions and vesting for ADP testing, and relieves ACP and top-heavy testing where the conditions are satisfied. The trade-offs between the two designs are covered in our overview of safe harbor plans for small businesses.

Profit sharing and money purchase pension plans

Both are employer-funded and neither accepts elective deferrals. The difference is the nature of the obligation. A profit sharing plan commonly gives the employer discretion over whether and how much to contribute for a year, within the allocation formula the document sets out. A money purchase pension plan states a fixed contribution the employer is required to make. Profit sharing features are frequently combined with a 401(k) arrangement in a single plan document.

403(b) plans

A 403(b) plan is available to public school systems and to certain organizations described in Code section 501(c)(3), rather than to employers generally. It permits elective deferrals subject to the same section 402(g) limit that applies to 401(k) deferrals, and it has its own rules on universal availability and on permitted funding vehicles. Our separate explainer covers how a 403(b) plan works.

SEP and SIMPLE arrangements

These are simplified structures with lower administrative requirements and lower limits. For 2026 the maximum employer contribution to a SEP is $72,000, SEP compensation is capped at $360,000, and the minimum compensation for SEP participation is $800. For SIMPLE plans, the 2026 employee contribution limit is $17,000, with a catch-up of $4,000 for participants age 50 and over, and $5,250 for participants who turn 60, 61, 62, or 63 during the year. All of these figures are from the IRS cost-of-living table for 2026.

ESOPs and plans holding employer stock

An employee stock ownership plan is a defined contribution plan designed to invest primarily in qualifying employer securities. For 2026 the ESOP limits published by the IRS are $1,455,000 and $290,000, which are the amounts used in applying the distribution period rules under Code section 409(o). A plan holding employer securities also carries a higher ERISA bonding maximum, which is covered in our article on ERISA fidelity bond requirements. A related but distinct arrangement is the qualified employer securities transaction used in business financing, described in our guide to how the ROBS transaction works.

Starter 401(k) and SARSEP arrangements

Two narrower structures appear in the category. A starter 401(k) deferral-only arrangement, added by SECURE 2.0 for employers that do not maintain another plan, permits employee deferrals with no employer contributions and applies its own lower deferral limit rather than the general section 402(g) figure. A salary reduction SEP, or SARSEP, is a SEP that accepts elective deferrals, and no new SARSEP may be established after 1996, so the arrangements that remain are pre-existing ones.

One-participant plans

A plan covering only an owner, or an owner and spouse, with no other eligible employees is still a defined contribution plan and the section 415(c) and 402(g) limits apply to it. What differs is the reporting and the coverage of Title I of ERISA. A plan with no employees other than the owner and spouse is generally not covered by Title I, and it files a Form 5500-EZ rather than the full return, subject to the filing thresholds. Where the business hires an employee who becomes eligible, that analysis changes for the plan year in question.

Pooled employer plans

A pooled employer plan is a single defined contribution plan in which unrelated employers participate, administered by a pooled plan provider that takes on named fiduciary and administrative roles. The structure was made available by the SECURE Act and is discussed in our piece on pooled employer plans and fiduciary responsibility.

The 2026 Dollar Limits That Apply

The figures below are the 2026 limits as published by the IRS, which reflect Notice 2025-67 and were announced in IR-2025-111. They apply to the 2026 plan year and are adjusted annually.

Our annual summary of the 2026 IRS contribution maximums covers the same figures alongside the IRA and other thresholds.

How the Contribution Types Interact With the Limits

Two separate limits operate at the same time, and they count different things. The section 402(g) limit of $24,500 for 2026 is a limit on one participant’s elective deferrals across plans, and it is a calendar-year limit that follows the individual. The section 415(c) limit of $72,000 for 2026 is a limit on everything allocated to that participant’s account in one plan for the year, which includes deferrals, matching and nonelective contributions, after-tax contributions, and reallocated forfeitures. The IRS sets out how the contribution types are treated on its page covering retirement plan contributions.

Catch-up contributions and the Roth catch-up requirement

Catch-up contributions sit outside the section 415(c) limit, so a participant eligible for the age 50 catch-up can receive annual additions above $72,000 by that amount. The age-based figures do not stack: a participant who turns 60 through 63 during 2026 uses the $11,250 figure instead of the $8,000 figure, not on top of it.

A separate condition applies to who may make catch-up contributions on a pre-tax basis. For 2026, a participant whose prior-year FICA wages from the plan’s sponsoring employer exceeded $150,000 makes catch-up contributions as designated Roth contributions. Where a plan does not provide a Roth feature, the practical consequence is that affected participants have no catch-up option under that plan until the document is amended. Whether a given plan provides a Roth feature is determined by its plan document.

Employer matching and nonelective contributions

Matching contributions are conditioned on participant deferrals and nonelective contributions are not. Both count toward the section 415(c) limit, both are subject to the section 401(a)(17) compensation cap of $360,000 for 2026 in the allocation formula, and both are subject to the vesting schedule the plan document sets. Where the plan permits it, matching contributions may be made on a Roth basis, in which case they are includible in the participant’s income.

After-tax contributions

After-tax contributions that are neither pre-tax deferrals nor designated Roth contributions are permitted only where the plan document provides for them. They are not subject to the section 402(g) deferral limit, they do count toward the section 415(c) annual additions limit, and they are included in ACP testing.

Eligibility, Automatic Enrollment, and Vesting

Age and service conditions

A plan may condition participation on age and service, within the maximums the Code allows. The general limits are age 21 and one year of service, with a longer service condition permitted for certain plans that provide full and immediate vesting. A plan may be more generous than the maximum. What applies to a particular plan is set out in that plan’s document.

Long-term part-time employees

Separate rules require that certain part-time employees be permitted to make elective deferrals even where they do not satisfy the plan’s regular service condition. The SECURE Act introduced the requirement using three consecutive years of at least 500 hours, and SECURE 2.0 reduced that to two consecutive years. Our overview of long-term part-time employee eligibility covers how the counting works and which contributions the rule reaches.

Automatic enrollment for newer plans

Code section 414A, added by SECURE 2.0, requires certain 401(k) and 403(b) plans established after December 29, 2022 to include an automatic enrollment feature with automatic escalation, effective for plan years beginning after December 31, 2024. The requirement carries exceptions, including for employers that normally employ 10 or fewer employees, businesses in existence for less than three years, church plans, and governmental plans. Plans established on or before December 29, 2022 are not subject to it, though they may adopt automatic enrollment voluntarily, and our article on automatic enrollment covers how those designs operate.

Vesting

Elective deferrals are required to be fully vested. Employer contributions may be subject to a vesting schedule within the maximums the Code permits, which for defined contribution plans are a three-year cliff schedule or a six-year graded schedule. Safe harbor contributions and certain other contribution types carry their own vesting conditions. Amounts a participant forfeits on leaving before full vesting are applied as the plan document directs.

Nondiscrimination Testing and Ongoing Compliance

A defined contribution plan is tested each year to confirm it has not operated in favor of higher-paid employees. Which tests apply depends on the plan’s design.

Coverage testing

Code section 410(b) tests whether the group of employees actually benefiting under the plan is broad enough relative to the workforce, using either the ratio percentage test or the average benefit test. The test operates on who benefits rather than on who is eligible, so a plan can satisfy its eligibility terms and still have a coverage result to address. Related employers may be required to be treated as a single employer for this purpose under the controlled group and affiliated service group rules, which is one of the points where the answer depends on facts outside the plan document.

ADP and ACP testing

The actual deferral percentage test compares average elective deferral rates for highly compensated employees against the rates for everyone else. The actual contribution percentage test does the same for matching and after-tax contributions. For 2026 the highly compensated employee threshold is $160,000, applied to compensation for a plan year to determine status for the following plan year, and ownership is a separate route to that status independent of pay.

A safe harbor 401(k) design removes the ADP test, and removes ACP testing where its conditions are met. A SIMPLE 401(k) structure removes both. Where a test is not passed, the correction routes include returning excess amounts to the affected participants within a stated period or making an additional employer contribution, and which routes are available depends on the plan document and the timing.

The top-heavy determination

Under Code section 416 a plan is top-heavy for a plan year where more than 60 percent of account balances belong to key employees as of the determination date. For 2026 the key employee compensation threshold is $235,000. A top-heavy plan is subject to minimum contribution and minimum vesting requirements for non-key employees. A safe harbor plan meeting the stated conditions is treated as not top-heavy, which is one of the reasons the design is used by employers whose ownership holds a large share of plan assets.

The annual limit tests

The section 415(c) annual additions limit and the section 402(g) deferral limit are tested per participant rather than across the plan. Section 402(g) is a calendar-year limit that follows the individual, so a participant who deferred to another employer’s plan earlier in the year can exceed it without the current plan having done anything wrong, and the correction depends on which plan the excess is assigned to.

Depositing participant contributions

Amounts withheld from pay become plan assets, and the Department of Labor’s regulation at 29 CFR 2510.3-102 requires that they be transmitted to the plan as of the earliest date on which they can reasonably be segregated from the employer’s general assets. A safe harbor is available for plans with fewer than 100 participants where the deposit is made within seven business days of withholding. Deposit timing is a function of how payroll and the plan are connected, which is the subject of our payroll services page.

Bonding, fiduciary duties, and correction

ERISA section 412 requires that persons who handle plan funds be covered by a fidelity bond, and the amount is calculated from funds handled rather than from plan assets. Our article on what an ERISA fidelity bond covers sets out the calculation and the exemptions. Where an operational failure has occurred, the IRS maintains correction programs described on its correcting plan errors pages, and our consulting and correction services page covers the formal routes.

What participants have to be given

Several disclosures run to participants rather than to an agency. The summary plan description describes the plan’s terms in plain language. Benefit statements are required under ERISA section 105, at least quarterly for a participant-directed plan and at least annually otherwise. The Department of Labor’s participant disclosure regulation at 29 CFR 2550.404a-5 requires that participants in a participant-directed plan receive stated plan-level and investment-level information, including the fees and expenses charged against their accounts. A summary annual report follows the Form 5500 filing. Where a plan uses automatic enrollment or a safe harbor design, further annual notices apply, and which notices a particular plan owes follows from its design.

Annual Reporting on the Form 5500

Most defined contribution plans subject to ERISA file an annual return in the Form 5500 series. Which form and which schedules apply depends on participant count and plan characteristics: the Form 5500-SF is available to certain small plans meeting stated conditions, the Form 5500-EZ applies to one-participant plans and to certain foreign plans, and the full Form 5500 applies otherwise. The current forms and instructions are published on the Department of Labor’s Form 5500 series page.

Plans with 100 or more participants generally include an independent qualified public accountant’s report with the filing. A regulation waives that requirement for plans with fewer than 100 participants where conditions on qualifying plan assets, bonding, and participant disclosure are met, which is covered in our fidelity bond article. The audit itself is the subject of our large plan audit services page.

Filed returns are publicly available through the Department of Labor’s EFAST2 filing search, and our guide to how to get a copy of a plan’s Form 5500 covers retrieving and reading one. A SEP maintained on an IRS model form does not file a Form 5500 for the arrangement itself, which is one of the differences that distinguishes it from a qualified plan.

Distributions and Required Minimum Distributions

When amounts become distributable

A defined contribution plan may distribute an account only on the events its plan document permits, within what the Code allows. For elective deferrals the general distributable events are separation from service, death, disability, attainment of age 59 and a half, plan termination, and hardship where the plan provides for it. Employer contributions may be subject to different conditions. Amounts distributed before age 59 and a half are generally subject to an additional 10 percent tax unless an exception applies, and our overview of distributions before retirement covers the general framework.

Loans and hardship distributions

Neither is required, and both exist only where the plan document provides for them. A participant loan that meets the conditions in ERISA section 408(b)(1) and Code section 72(p) is not treated as a distribution, and those conditions include a limit of the lesser of $50,000 or half the vested account balance, a repayment term generally not exceeding five years except for a principal residence, level amortization, and a reasonable interest rate. A loan that falls outside those conditions can become a taxable deemed distribution.

A hardship distribution is available from a 401(k) plan where the plan permits it and the participant has an immediate and heavy financial need, and it is limited to the amount necessary to satisfy that need. Hardship amounts are includible in income and, unless an exception applies, are subject to the additional 10 percent tax. Whether a particular circumstance qualifies is determined under the plan’s own terms and the applicable rules rather than at the participant’s election.

Required minimum distributions

Distributions have to begin once a participant reaches the required beginning date, which SECURE 2.0 set at age 73 for participants reaching that age in the applicable years. The amount is calculated from the account balance and a life expectancy factor. Designated Roth accounts in a plan are no longer subject to lifetime required minimum distributions. The IRS publishes the required beginning dates and calculation rules on its required minimum distributions pages, and our note on the April 1 deadline covers the first-year timing.

Rollovers

An eligible rollover distribution may generally move to another eligible retirement plan or to an individual retirement arrangement, and a direct trustee-to-trustee transfer avoids the withholding and the 60-day constraint that apply to a distribution paid to the participant. Whether a plan accepts incoming rollovers is a plan document question.

How Contributions Are Treated for Tax Purposes

The employer side

Employer contributions to a qualified defined contribution plan are generally deductible under Code section 404, subject to the deduction limits that section imposes and to the requirement that amounts be paid by the applicable deadline for the taxable year. Elective deferrals reduce the participant’s taxable wages rather than producing an employer deduction of their own, and they remain subject to FICA. The IRS covers the employer treatment for smaller plans in Publication 560.

Credits available to smaller employers

Three separate credits can apply where an employer establishes a plan, and they are claimed on Form 8881:

• The startup cost credit under Code section 45E. Generally 50 percent of qualified startup costs, increased to 100 percent for employers with 1 to 50 employees under SECURE 2.0, with employers of 51 to 100 employees remaining at 50 percent. The credit is limited to the greater of $500, or the lesser of $250 for each non-highly compensated employee eligible to participate or $5,000, and it runs for the first credit year and each of the two following years. An eligible employer is one that had no more than 100 employees in the preceding tax year who received at least $5,000 of compensation.
• The employer contribution credit under Code section 45E, added by SECURE 2.0. An additional amount based on an applicable percentage of the employer’s contributions to the plan, excluding elective deferrals. It is not available for defined benefit plans, which is one of the places the two structures are treated differently in the Code rather than just in operation.
• The automatic enrollment credit under Code section 45T. $500 per year over a three-year period beginning with the first tax year in which the employer includes an eligible automatic contribution arrangement.

A further credit under Code section 45AA relates to military spouse participation in a defined contribution plan meeting stated conditions. Which credits an employer can claim, and in what amounts, depends on employee counts and costs for the years in question, and the IRS sets out the mechanics in the instructions to Form 8881.

The participant side

Pre-tax deferrals and employer contributions are not included in the participant’s income when contributed, and investment earnings are not taxed while they remain in the plan. Amounts are included in income when distributed, other than amounts attributable to designated Roth contributions that meet the conditions for a qualified distribution and any return of after-tax basis. Distributions before age 59 and a half are generally subject to an additional 10 percent tax unless an exception applies.

Where State Retirement Mandates Fit

A growing number of states require employers of a certain size to either offer a qualifying retirement plan or enroll employees in a state-facilitated program. A defined contribution plan is one of the ways an employer satisfies such a requirement, and which plans qualify is defined by each state’s own statute and program rules rather than by federal law. Our overview of state retirement plan mandates covers which states have them and what triggers them, and our note on state-approved qualifying plans covers what generally counts.

Working With a Third-Party Administrator

The recurring work on a defined contribution plan includes recordkeeping and participant accounting, the annual nondiscrimination and limit testing, preparation of the Form 5500 and any required schedules, distribution and loan processing, and the participant notices the plan is required to deliver. Which of those a given engagement covers is determined by the service agreement rather than by a standard division of labor, and our pages on plan administration and recordkeeping describe those functions. Our overview of how to choose a third-party administrator covers the questions that distinguish one scope of service from another.

Questions That Come Up on This Requirement

What is a defined contribution plan?

A defined contribution plan is a retirement plan that defines what is contributed to an individual account for an employee rather than the benefit payable at retirement. Contributions are allocated to the account, the account is invested, and the participant’s benefit is the account balance including investment gains and losses. The 401(k) plan is the most widely recognized example, and the category also includes profit sharing plans, money purchase pension plans, 403(b) plans, SEPs, SIMPLE plans, and employee stock ownership plans.

What is the difference between a defined contribution plan and a defined benefit plan?

A defined contribution plan defines what goes in and a defined benefit plan defines what comes out. In a defined contribution plan the participant’s benefit is the account balance, so investment results change the benefit. In a defined benefit plan the benefit is promised by formula, so investment results change what the employer has to contribute rather than what the participant receives. The limits are measured at opposite ends as well: for 2026, annual additions to a defined contribution account are capped at $72,000 under Code section 415(c), while the annual benefit from a defined benefit plan is capped at $290,000 under section 415(b). Defined benefit plans also require an enrolled actuary and are generally covered by the Pension Benefit Guaranty Corporation.

Is a 401(k) a defined contribution plan?

Yes. A 401(k) plan is a defined contribution plan that permits participants to elect deferrals from pay. The plan document determines whether the employer also makes matching or nonelective contributions. Other defined contribution plans, such as profit sharing and money purchase pension plans, do not accept elective deferrals.

What are the types of defined contribution plans?

The category includes 401(k) plans and safe harbor 401(k) plans, profit sharing plans, money purchase pension plans, 403(b) plans for public schools and certain tax-exempt employers, SIMPLE 401(k) plans, SEP arrangements, employee stock ownership plans, and pooled employer plans covering unrelated employers. They differ in who may sponsor them, whether employees can defer from pay, what the employer is required to contribute, and which nondiscrimination tests apply.

What is the 2026 limit for a defined contribution plan?

For 2026, total annual additions to one participant’s account are limited to $72,000 under Code section 415(c), not counting age 50 catch-up contributions. Within that, elective deferrals are limited to $24,500 under section 402(g), with an additional $8,000 catch-up at age 50 and over, or $11,250 for participants who turn 60, 61, 62, or 63 during the year. Compensation taken into account is capped at $360,000. These figures come from the IRS cost-of-living table for 2026, which reflects Notice 2025-67.

Who bears the investment risk in a defined contribution plan?

The participant does, in the sense that the account balance rises and falls with the investments and the benefit is that balance. The employer is not obligated to make up investment losses. That does not remove the employer’s other obligations: the people who select and monitor the plan’s investments are fiduciaries under ERISA and are subject to its standards of prudence and loyalty.

Does a defined contribution plan have to file a Form 5500?

Most defined contribution plans subject to ERISA file an annual return in the Form 5500 series. Which form applies depends on participant count and plan characteristics: the Form 5500-SF for certain small plans meeting stated conditions, the Form 5500-EZ for one-participant plans and certain foreign plans, and the full Form 5500 otherwise. A SEP maintained on an IRS model form does not file a Form 5500 for the arrangement itself.

Do employer contributions have to be vested immediately?

Elective deferrals are required to be fully vested. Employer contributions may be subject to a vesting schedule, within maximums the Code sets for defined contribution plans of a three-year cliff schedule or a six-year graded schedule. Safe harbor contributions and certain other contribution types carry their own vesting conditions. A plan document may provide faster vesting than the maximum.

Can an employer sponsor both a defined contribution and a defined benefit plan?

Yes. The two structures are not mutually exclusive at the employer level, and the limits apply separately to each plan. A cash balance plan is a defined benefit plan that states the benefit as a hypothetical account balance, which presents like a defined contribution plan to participants while remaining a defined benefit plan for funding, actuarial, and limit purposes. Whether a combination fits a particular employer is a design question for that employer and its advisors.

Are there tax credits for starting a defined contribution plan?

Yes, for employers that qualify. The startup cost credit under Code section 45E is generally 50 percent of qualified startup costs, increased to 100 percent for employers with 1 to 50 employees under SECURE 2.0, limited to the greater of $500 or the lesser of $250 per non-highly compensated eligible employee or $5,000, for the first credit year and the two following years. A separate credit under section 45E applies to employer contributions and is not available for defined benefit plans. A credit of $500 per year for three years is available under section 45T where the plan includes an eligible automatic contribution arrangement. All are claimed on Form 8881, and eligibility depends on employee counts for the years in question.

Do defined contribution plans satisfy state retirement mandates?

A defined contribution plan is one of the ways an employer can satisfy a state requirement to offer a retirement plan, but what qualifies is defined by each state’s own statute and program rules rather than by federal law. The triggering employer size and the registration deadlines also vary by state.

Sources

Every substantive statement above is drawn from the following. Links were verified at the time of writing.

• Internal Revenue ServiceTypes of retirement plansThe agency’s overview of the plan structures available to employers, including the defined contribution and defined benefit categories.
• Internal Revenue ServiceCOLA increases for dollar limitations on benefits and contributionsThe published table of annual limits. Every 2026 dollar figure in this article comes from here.
• Internal Revenue ServiceNotice 2025-67The notice setting the 2026 cost-of-living adjustments for qualified plan limits.
• Internal Revenue ServiceIR-2025-111, 401(k) limit increases to $24,500 for 2026The announcement of the 2026 adjustments.
• Internal Revenue ServiceRetirement topics: contributionsHow the contribution types are treated and how the deferral and annual additions limits operate.
• Internal Revenue ServiceRetirement topics: required minimum distributionsRequired beginning dates and the calculation rules.
• Internal Revenue ServiceCorrecting plan errorsThe correction programs available where a plan has an operational failure.
• Internal Revenue ServiceRetirement plans frequently asked questionsThe agency’s answers on plan operation, testing, and reporting questions.
• U.S. Department of Labor, Employee Benefits Security AdministrationForm 5500 series forms and instructionsThe annual reporting forms, schedules, and instructions.
• U.S. Department of Labor, Employee Benefits Security AdministrationEFAST2 Form 5500 series searchThe public search for filed Form 5500 and Form 5500-SF returns.
• U.S. Department of Labor, Employee Benefits Security AdministrationMeeting Your Fiduciary ResponsibilitiesThe Department’s overview of the fiduciary duties that apply to running a plan and selecting its investments.
• Internal Revenue ServicePublication 560, Retirement Plans for Small BusinessThe employer deduction rules and the startup, contribution, and automatic enrollment credits as they apply to smaller employers.
• Internal Revenue ServiceInstructions for Form 8881How the section 45E, 45T, and 45AA credits are computed and claimed.
• Internal Revenue Code and ERISACode section 415, the annual additions and benefit limits, and section 402, the elective deferral rules. Also sections 72(p), 401(a)(17), 404, 408(b)(1), 410(b), 411(a), 414A, 416, 409(o), 45E, 45T and 45AA; ERISA sections 105, 404(c) and 412; and 29 CFR 2510.3-102, 2550.404a-5 and 2550.404c-5The statutory and regulatory provisions behind the limits, eligibility conditions, vesting schedules, testing, bonding, and deposit timing described above.