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401K Definition

A 401(k) is a retirement savings plan sponsored by an employer that allows employees to invest a portion of their paycheck before taxes are taken out.

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Last Updated: December 19, 2025

Small business owners are grateful for good employees. Offering them competitive pay and quality benefits can help business owners retain the very best employees. A retirement plan is an important benefit to many workers; it can be a great way for employers to show their team that they care. A popular plan is the 401 (k).

The Employee Retirement Income Security Act (ERISA) doesn’t require employers to give retirement plans to their employees, but employers do have to follow certain rules if they do. The rules to follow depend on the kind of retirement plan chosen. This guide will clarify what a 401(k) is and some of the plan’s primary rules and features. 

What is a 401(k)?

401k defined

First off, 401(k) stands for retirement plans qualified under Section 401(k) of the Internal Revenue Code. In many 401 (k)’s, an employer contributes part of a participating employee’s wages to a retirement account for the employee before withholding taxes from their paycheck. These accounts serve as “savings accounts” with specific perks for employees’ futures. 

But entrepreneurs like choices, and there are choices available among 401(k) options. The plan offered can be a:

  • Profit-sharing plan
  • Stock bonus plan 
  • Pre-ERISA money purchase pension
  • Rural cooperative plan

Depending on how an entrepreneur chooses to handle the funds in a 401 (k), a company’s employee accounts might earn significant interest or returns on investments. Employees might not only save money for a rainy day but also see their money grow beyond the amount of their contributions.

Is every 401(k) the same?

Not every 401(k) is the same. The definitions and rules change depending on the kind of 401(k) an entrepreneur chooses for their business. The three kinds of pre-tax 401 (k) plans that employers provide are:

  • Traditional 401(k) plans. Employers deduct employees’ contributions from their paychecks, and employers must comply with certain nondiscrimination rules.
  • Safe harbor 401(k) plans. Employees make contributions from their wages; employers must give certain notices, and employers must make contributions that vest fully and immediately.
  • SIMPLE 401(k) plans. Employees make contributions from their wages and can’t receive benefit accruals under other employer plans. To participate, employers must have 100 or fewer employees earning $5,000 or more per year, and employers must make fully vested contributions.

Employers can also sponsor a post-tax Roth 401(k) for their employees. 

Entrepreneurs who are considering offering benefits would be wise to consult with a financial professional to discuss different capabilities and options. 

401(k) Advantages

Having a 401(k) retirement plan can be a win-win decision for a business. 401(k) benefits can help keep a workforce happy and attract top talent. Also, a small business gets the added perks of federal income tax deductions and certain tax deferrals when it sponsors a 401(k) for its employees. 

401(k) Disadvantages

There are many upsides to offering a 401(k) retirement plan, but it’s still a lot of extra work and cost. When a business sponsors a 401(k), it might have to follow several rules about contribution amounts, providing notice to employees, and making vested contributions.  

A 401(k) can help entrepreneurs take good care of their employees and receive tax advantages

With a 401(k) retirement plan, an employer can help their team save some hard-earned cash to set up a better future. Not only can a 401(k) help entrepreneurs foster a happy workforce, but it can also give the company considerable tax benefits. While setting up a plan can require additional investment of time and resources, it can provide a business with numerous benefits that make the effort worthwhile.

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Disclaimer: The content on this page is for information purposes only and does not constitute legal, tax, or accounting advice. For specific questions about any of these topics, seek the counsel of a licensed professional.

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Written by ZenBusiness Editorial Team

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