Retirement Plan

A retirement plan is a savings program designed to help people build income for retirement. Many plans are funded through payroll deductions and, in some cases, employer contributions. Common workplace retirement plans include 401(k) plans, SIMPLE IRAs and SEP plans, as well as pension-style defined benefit plans. Retirement plans can offer tax advantages, help employees save consistently and support long-term financial goals.

Employers that sponsor a plan may have important responsibilities under federal rules, especially around plan governance and service providers.

What Is a Retirement Plan?

A retirement plan is a structured way to set aside money for retirement. In many workplace plans, employees may designate a certain amount of money to be deducted, pre-tax, from their pay. Employers may also contribute. The money is generally invested so it can grow over time. Individuals also can set up their own retirement plans.

Workplace retirement plans can be a significant part of an employee benefits package. From an employer perspective, a clear plan design and straightforward administration can make the experience better for both employees and internal teams. Many businesses use an HR outsourcing company to manage retirement plans.

Which Types of Retirement Plans Do Employers Offer?

Employers can choose from several types of retirement plans. The best fit often depends on workforce size, desired features and how much administration the employer wants to take on.

Here is a comparison of common options:

Plan Type	Who It’s For	Who Contributes	Typical Admin Complexity	One Thing To Know
401(k) (defined contribution)	Many private-sector employers	Employees and, optionally, employers	Medium to high	Employees often choose investments from a plan lineup
SIMPLE IRA	Smaller employers that meet eligibility rules	Employees and employers	Low to medium	Employer contributions are generally required under SIMPLE rules
SEP (SEP IRA)	Often used by small employers and self-employed owners	Employers (generally)	Low	Employer decides each year whether to contribute and how much
Defined benefit plan (pension)	Employers offering a promised benefit	Employers (typically)	High	Benefit is usually based on a formula tied to pay and service
Pooled employer plan (PEP)	Employers that want a shared plan structure	Varies by plan design	Medium	Multiple employers participate in one plan structure

Retirement plans are governed by written plan documents. Those documents explain eligibility, contributions, vesting and how the plan operates.

How Does a 401(k) Retirement Plan Work?

A 401(k) plan is a type of defined contribution plan. In general terms:

During an enrollment period, employees are notified of the retirement plan options available to them. Participants typically select investments from options offered under the plan.
Employees may elect to defer part of their compensation into the plan through payroll deductions.
Employers may contribute to the plan, providing matching contributions or nonelective contributions.
The account balance reflects contributions plus or minus investment gains and losses.

A 401(k) plan can include additional design features, such as automatic contribution increases, depending on how the plan is set up.

What Are Key Employer Responsibilities Under ERISA?

Many private-sector, employer-sponsored retirement plans are subject to ERISA, a federal law that sets standards for plan governance and participant protections.

If you offer an ERISA-covered retirement plan, you are generally considered the plan sponsor. Depending on how the plan is run, you may also be a fiduciary. A fiduciary is a person or entity with discretionary authority or control over plan management, plan administration or plan assets.

Key responsibilities often include:

Following the plan’s written terms (as long as those terms follow the law).
Making prudent decisions about plan administration and investments when you have discretion.
Monitoring fees and the services you pay for.
Selecting and monitoring service providers, such as recordkeepers, third-party administrators (TPAs) or investment professionals.
Keeping required disclosures and reporting on track, when applicable.

Using outside providers can help with day-to-day benefits administration, but it does not automatically remove all plan sponsor responsibilities. The division of responsibilities depends on the contracts in place and the specific roles each party takes on.

What Is Vesting and How Does It Work?

Vesting refers to an employee’s ownership of certain amounts in the plan. Employee salary deferrals are generally 100% vested because they come from the employee’s pay. Employer contributions may vest immediately or over time, depending on the plan’s rules.

Vesting matters because it affects what an employee can keep if they leave the company. For example, an employee might be fully entitled to their own contributions but only partially entitled to employer contributions if the plan uses a multi-year vesting schedule.

When Does It Make Sense to Outsource Retirement Plans?

Many employers use HR outsourcing providers to help run their retirement plans. Others offer an HR outsourcing company’s retirement plans to their employees.

A small or medium-sized business that joins a PEO (professional employer organization), for example, might offer the PEO’s sponsored 401(k) plan to employees. A PEO might also help by shouldering the responsibility of being a named co-fiduciary for its sponsored plan. Retirement plans are heavily regulated, and PEOs may help SMBs mitigate their risk by providing compliance support.

By outsourcing retirement plans, a business may receive:

Automated contribution and data submission.
Compliance testing and Form 5500 filing.
Investment selection and monitoring.
Loan and distribution processing.

It can make sense to outsource retirement plan services when:

Plan rules are too complex to manage in-house.
The employer wants structured support for administration.
Internal teams want clearer processes for eligibility, contributions and participant communications.
The costs of managing and/or providing retirement benefits is prohibitive for an SMB.

FAQ

Are employers required to offer a retirement plan?

In general, employers are not required by federal law to offer a retirement plan. Many employers choose to offer one as part of their overall benefits approach.

What is the difference between a 401(k) and a pension plan?

A 401(k) is typically a defined contribution plan where the retirement benefit depends on contributions and investment performance. A pension plan is generally a defined benefit plan that promises a benefit based on a formula.

What is automatic enrollment and how does it work?

Automatic enrollment is a plan feature that enrolls eligible employees by default at a stated contribution rate, unless they opt out or choose a different rate.

What does it mean to be a retirement plan fiduciary?

A retirement plan fiduciary is someone with discretionary authority over plan management, plan administration or plan assets. Fiduciaries are expected to act in the interest of participants and beneficiaries.