Define: 401(K) Plan

401(K) Plan
401(K) Plan
Quick Summary of 401(K) Plan

A 401(k) plan is a retirement plan offered by employers to their employees. It allows employees to save money for retirement and delay taxes until they withdraw the funds. Employees can contribute a set amount each year, and employers may also contribute. The funds in the 401(k) account can be invested in various options. Once employees reach a specific age, they can withdraw the funds without penalty. However, early withdrawals incur a penalty. Additionally, there is a variation called a Roth 401(k) that taxes contributions upfront but allows tax-free withdrawals.

What is the dictionary definition of 401(K) Plan?
Dictionary Definition of 401(K) Plan

A 401(k) plan is a retirement plan offered by employers to their employees, allowing them to save money for retirement while deferring taxes. It is named after Section 401(k) of the Internal Revenue Code. Employees can contribute a portion of their salary to their 401(k) plan each year, up to a limit set by the IRS. Employers may also contribute to the plan, often matching a percentage of the employee’s contribution. For instance, if an employee contributes $1000, their employer may contribute an additional $500. Contributions to a 401(k) plan are tax-free until the employee starts withdrawing the money during retirement, at which point they are taxed as income. If an employee withdraws money from their 401(k) before a certain age, they may face a penalty tax in addition to regular income taxes. Additionally, there are Roth 401(k) plans that tax contributions before they enter the account but allow tax-free withdrawals during retirement. Employees can contribute to a traditional 401(k) and a Roth 401(k), but their total contributions cannot exceed the IRS limit. For example, if an employee earns $50,000 annually and contributes 10% of their salary to their 401(k), they would contribute $5,000 annually. If their employer matches 50% of their contribution, they would receive an additional $2,500 from their employer. The employee’s contributions and any earnings on those contributions would not be taxed until they began withdrawing the money during retirement.

Full Definition Of 401(K) Plan

The 401(k) plan, established under the U.S. Internal Revenue Code, is a defined contribution pension account designed to enable employees to save and invest for their retirement on a tax-deferred basis. Named after the section of the code that created it, 401(k) plans are prevalent among U.S. employers and are integral to the retirement planning of millions of Americans. This legal overview will examine the origins, regulations, compliance requirements, benefits, and potential pitfalls associated with 401(k) plans, providing a comprehensive understanding of their operation and legal framework.

Historical Context

The 401(k) plan was created by the Revenue Act of 1978 and became effective in 1980. Initially, it was intended as a supplemental savings account for executives, but it quickly gained popularity among all employee groups. By allowing pre-tax contributions, the 401(k) offered a significant tax advantage over traditional savings methods, encouraging widespread adoption.

Legal Framework and Regulations

Establishment and Administration

To establish a 401(k) plan, an employer must draft a written plan document that outlines the plan’s terms and conditions. This document must comply with the Employee Retirement Income Security Act of 1974 (ERISA), which sets standards to protect participants. ERISA requires the plan to provide participants with information about plan features and funding and sets minimum standards for participation, vesting, benefit accrual, and funding.

Fiduciary Responsibilities

ERISA imposes fiduciary duties on those managing the 401(k) plan. Fiduciaries must act solely in the interest of plan participants and beneficiaries to provide benefits and defray reasonable expenses. They must also act prudently, diversify plan investments to minimise the risk of large losses and follow the terms of the plan documents.

Contribution Limits

The Internal Revenue Service (IRS) sets annual limits on 401(k) plan contributions. For 2024, the elective deferral limit is $19,500, with an additional catch-up contribution limit of $6,500 for participants aged 50 and over. Employer contributions, combined with employee contributions, must not exceed the lesser of 100% of the employee’s compensation or $66,000.

Vesting and Non-Discrimination Testing

Vesting refers to the degree to which an employee owns the employer’s contributions to their 401(k) account. While employees are always 100% vested in their own contributions, employer contributions vest according to a schedule defined in the plan document. The IRS mandates nondiscrimination testing to ensure that 401(k) plans do not disproportionately benefit highly compensated employees (HCEs) over non-HCEs. These tests include the Actual Deferral Percentage (ADP) and Actual Contribution Percentage (ACP) tests.

Tax Implications

Tax Deferral

One key benefit of a 401(k) plan is the tax deferral on contributions and investment gains. Contributions are made with pre-tax income, reducing the employee’s annual taxable income. The funds grow tax-deferred until withdrawal, typically in retirement, when they are taxed as ordinary income.

Roth 401(k) Option

Introduced in 2006, the Roth 401(k) allows employees to contribute after-tax dollars, with qualified distributions being tax-free. This option provides tax diversification, enabling employees to better manage their tax liability in retirement.

Required Minimum Distributions (RMDs)

Participants must begin taking RMDs from their 401(k) accounts at age 72. The amount of the RMD is based on the account balance and the participant’s life expectancy. Failure to take RMDs can result in substantial penalties.

Compliance and Reporting Requirements

Form 5500

Employers must file an annual Form 5500 with the Department of Labor (DOL), providing information about the plan’s financial condition, investments, and operations. This form helps the DOL and IRS ensure compliance with ERISA and tax regulations.

Participant Disclosure

ERISA mandates that plan administrators provide participants with a Summary Plan Description (SPD), outlining the plan’s key features and their rights and obligations. Additionally, participants must receive periodic statements detailing their account balance and investment performance.

Plan Design and Investment Options

Plan Design

Employers can customise their 401(k) plans to meet their workforce’s needs, including features like automatic enrolment, employer matching contributions, and loan provisions. Automatic enrolment increases participation rates by enrolling employees by default, with the option to opt-out.

Investment Options

Employers must offer diversified investment options, typically including mutual funds, target-date funds, and stable-value funds. Participants can choose how to allocate their contributions among these options, allowing for a tailored investment strategy.

Benefits and Advantages

Retirement Savings Incentive

The primary advantage of a 401(k) plan is the opportunity to save for retirement with significant tax advantages. Combining pre-tax contributions, tax-deferred growth, and potential employer-matching contributions can significantly enhance retirement savings.


401(k) plans are portable, meaning employees can roll over their account balances into a new employer’s plan or an individual retirement account (IRA) when changing jobs. This portability ensures that employees can continue building their retirement savings without interruption.

Financial Education and Support

Many employers offer financial education and support services to help employees make informed decisions about their 401(k) plans. This assistance can include investment advice, retirement planning tools, and access to professional financial advisors.

Potential Drawbacks and Pitfalls

Market Risks

Investment in a 401(k) plan is subject to market risk, meaning the value of the investments can fluctuate based on market conditions. Participants may experience losses, especially if their investment choices are not appropriately diversified.

Fees and Expenses

401(k) plans can incur various fees and expenses, including administrative, investment management, and individual service fees. High fees can erode investment returns over time, making it crucial for participants to understand the fee structure of their plan.

Early Withdrawal Penalties

Withdrawals from a 401(k) account before age 59½ are generally subject to a 10% early withdrawal penalty and regular income taxes. There are exceptions for certain circumstances, such as disability or financial hardship, but these penalties can significantly reduce the amount of available retirement savings.

Legal Protections and Participant Rights

Anti-Alienation Provision

ERISA includes an anti-alienation provision that protects 401(k) plan assets from being assigned, garnished, or encumbered by creditors, except under specific circumstances such as Qualified Domestic Relations Orders (QDROs).

Participant Lawsuits

Participants can sue plan fiduciaries for breaches of their duties under ERISA. Successful lawsuits can result in the restoration of the plan’s losses and other equitable relief.

Recent Developments and Future Trends

Legislative Changes

Recent legislative changes, such as the SECURE Act of 2019, have impacted 401(k) plans by increasing the RMD age from 70½ to 72 and allowing long-term part-time employees to participate. Ongoing legislative proposals aim to enhance retirement savings opportunities and protections further.

Technology and Innovation

Advancements in technology have led to the development of robo-advisors and digital platforms that provide participants with personalised investment advice and retirement planning tools. These innovations are making it easier for individuals to manage their 401(k) accounts and make informed investment decisions.

Focus on Financial Wellness

Employers increasingly recognise the importance of financial wellness programs that address overall financial health, including debt management, budgeting, and retirement planning. Integrating these programs with 401(k) plans can improve employee engagement and outcomes.


The 401(k) plan remains a cornerstone of retirement planning in the United States, offering significant tax advantages and the potential for substantial retirement savings. However, navigating the legal and regulatory landscape of 401(k) plans requires careful attention to compliance requirements, fiduciary responsibilities, and participant rights. Employers must design and administer their plans to meet legal standards while providing valuable benefits to their employees. Conversely, participants must be proactive in understanding their plan options, managing investment risks, and maximising their retirement savings opportunities. With ongoing legislative changes and technological advancements, the 401(k) plan will continue to evolve, shaping the future of retirement savings in America.

401(K) Plan FAQ'S

A 401(k) plan is a retirement savings plan offered by employers to their employees. It allows employees to contribute a portion of their salary on a pre-tax basis, and the funds are invested in various investment options until retirement.

The contribution limits for a 401(k) plan are set by the Internal Revenue Service (IRS). For 2021, the maximum contribution limit is $19,500 for individuals under the age of 50. Individuals aged 50 and above can make an additional catch-up contribution of $6,500, bringing their total contribution limit to $26,000.

In general, you cannot withdraw money from your 401(k) plan before reaching the age of 59 ½ without incurring a penalty. However, there are certain exceptions, such as financial hardship or disability, that may allow for early withdrawals.

Yes, many 401(k) plans allow participants to take loans from their accounts. The maximum loan amount is usually the lesser of $50,000 or 50% of the vested account balance. However, it is important to note that taking a loan from your 401(k) plan may have tax implications and could impact your retirement savings.

When you change jobs, you have several options for your 401(k) plan. You can leave the funds in your previous employer’s plan, roll them over into your new employer’s plan, roll them over into an Individual Retirement Account (IRA), or cash out the funds. It is advisable to consult with a financial advisor to determine the best option for your specific situation.

Yes, you can contribute to both a 401(k) plan and an IRA. However, the contribution limits for each type of account are separate. For 2021, the maximum contribution limit for an IRA is $6,000 for individuals under the age of 50, with an additional catch-up contribution of $1,000 for individuals aged 50 and above.

Contributions to a traditional 401(k) plan are made on a pre-tax basis, meaning they are not included in your taxable income for the year. This allows you to reduce your current taxable income and defer taxes until you withdraw the funds in retirement.

Yes, self-employed individuals can contribute to a 401(k) plan. However, they would need to set up a solo 401(k) plan, also known as an individual 401(k) plan, which is specifically designed for self-employed individuals or small business owners with no employees other than a spouse.

If your employer goes bankrupt, your 401(k) plan is generally protected by federal law. The funds in your account are held in a trust separate from your employer’s assets, which helps safeguard your retirement savings. In most cases, you would still have access to your funds and the ability to roll them over into another retirement account.

Yes, non-U.S. citizens who are legally employed in the United States can contribute to a 401(k) plan, provided they meet the eligibility requirements set by their employer. However, it is important to consult with a tax advisor to understand any potential tax implications in your home country.

Related Phrases

This site contains general legal information but does not constitute professional legal advice for your particular situation. Persuing this glossary does not create an attorney-client or legal adviser relationship. If you have specific questions, please consult a qualified attorney licensed in your jurisdiction.

This glossary post was last updated: 11th June 2024.

Cite Term

To help you cite our definitions in your bibliography, here is the proper citation layout for the three major formatting styles, with all of the relevant information filled in.

  • Page URL:
  • Modern Language Association (MLA):401(K) Plan. DLS Solicitors. June 16 2024
  • Chicago Manual of Style (CMS):401(K) Plan. DLS Solicitors. (accessed: June 16 2024).
  • American Psychological Association (APA):401(K) Plan. Retrieved June 16 2024, from website:
Avatar of DLS Solicitors
DLS Solicitors : Family Law Solicitors

Our team of professionals are based in Alderley Edge, Cheshire. We offer clear, specialist legal advice in all matters relating to Family Law, Wills, Trusts, Probate, Lasting Power of Attorney and Court of Protection.

All author posts