401(k) deadlines for employers and employees

LAST REVIEWED Dec 12 2023
21 MIN READEditorial Policy

Key Takeaways

  • This article lists out 401(k) deadlines for both employers and employees.

  • We’ll also include action items and links where you can find more information.

  • Human Interest can help your plan meet these deadlines so you stay in compliance.

Whether you’re an employer or an employee, we believe that setting up a 401(k) plan is a great way to prepare for retirement and can also be a source of tax advantages.

  • For employers: To maximize the benefits of your 401(k) program, you must remember deadlines for key events — including those that affect plan administration and compliance — and for launching a safe harbor 401(k) plan.

  • For employees: You’ll want to track contribution deadlines and tax filings and when to expect communications from your employer (and/or plan sponsor) regarding your 401(k).

For your convenience, here’s a list of 401(k) deadlines for employers and employees, including action items and links to find additional information. Human Interest can help you understand and meet all of these deadlines to ensure your plan complies with ERISA.

Start a 401(k) with Human Interest

A Human Interest 401(k) plan can connect directly with your favorite payroll provider and has zero transaction fees.

For your convenience, here’s a list of 401(k) deadlines for employers and employees, including action items and links to find additional information. Human Interest can help you understand and meet all of these deadlines to ensure your plan complies with ERISA.

401(k) deadlines for employers

The following deadlines affect plan years ending 12/31.

January

February

March

April

May

June

July

August

September

October

November

December


January 1: Start of safe harbor 401(k) match

A safe harbor 401(k) plan is a type of 401(k) plan that ensures all employees at a company have some set of minimum contributions made to their individual 401(k) plans, regardless of their title, compensation, or length of service. In exchange for making the fixed employer contribution, employers get a “pass” on key 401(k) nondiscrimination tests.

If you already have a traditional 401(k) plan, you cannot add a safe harbor match in the middle of the year (although non-elective safe harbor plans can be added mid-year). January 1 is when existing 401(k) plans can begin anew as safe harbor matching 401(k) plans. 

Learn more: Safe harbor 401(k) plans explained

January 15: Prior year census data

The employer must provide the prior year’s census data to the plan’s recordkeeper, which contains pertinent information for each employee at the company, including:

  • Name

  • Date of birth

  • Date of hire

  • Termination date (if applicable)

  • Hours worked

  • Compensation and amounts contributed to the 401(k) during the year

The recordkeeper uses this census data to complete nondiscrimination testing following U.S. Department of Labor (DOL) and Internal Revenue Service (IRS) guidelines.

January 31: Issue Form 1099-R

Employers must send Form 1099-R to plan participants who received distributions during the previous year. 

Learn more: About Form 1099-R

February 15: Deadline for Q4 participant statements

Employers must send prior year fourth-quarter statements to participants by this date.

February 28: File Form 1099-R

Employers must file hardcopy Forms 1099-R with the IRS to report plan distributions made in the previous year by this date.

March 15: Corrective distributions 

Deadline for processing corrective distributions for failed actual deferral percentage (ADP) or actual contribution percentage (ACP) tests without a 10% excise tax for non-EACA (eligible automatic enrollment arrangement) plans. Failure to distribute corrective distributions by March 15 will result in a 10% penalty and require the employer to file an IRS Form 5330, Return of Excise Taxes Related to Employee Benefit Plans. 

March 15: Tax filing day for S corps, LLCs taxed as partnerships

Tax returns for S Corps and Partnerships are due unless an extension applies. This is also the deadline to deposit employer contributions for these entities and receive a tax deduction for the tax year if an extension does not apply.

March 31: File Form 1099-R electronically

If filing Forms 1099-R electronically with the IRS, employers must report distributions for the last year by this date.

April 1: Initial RMDs

Annual withdrawals called required minimum distributions (RMDs) are required from 401(k) plans. For participants turning age 73 on or after January 1 initial RMDs are required by April 1 of the following year. Subsequent RMDs must be taken by the end of the tax year (rather than April 1).

April 15: 402(g) refunds

Corrective distributions for IRC Section 402(g) excess deferrals must be made by this date for participants who contributed to more than one unrelated employer plan in the prior year for the participant to avoid tax consequences. (Note: Excess 402(g) deferrals to a single employer plan must be distributed by December 31 of the following year to avoid a plan operational error. )

See this IRS article for annual limits and any consequences of excess salary deferrals.

April 15: Tax day for C Corporations, Sole Proprietorships, LLCs Taxed as Corporations and Single-Member LLCs

Tax returns for C Corporations, Sole Proprietorships, LLCs taxed as corporations, and single-member LLCs are due. This is also the deadline to deposit employer contributions for these entities and receive a tax deduction for the tax year if an extension does not apply.

May 15: Deadline for Q1 participant statements

Employers must send the current year’s first-quarter statements to participants by this date.

June 30: Keep an eye on the special deadline for correcting distributions (for EACA plans)

This is the deadline for processing corrective distributions for failed ADP and ACP tests without a 10% excise tax for plans containing an EACA provision. Failure to distribute corrective distributions by June 30 will result in a 10% penalty and require the employer to file an IRS Form 5330, Return of Excise Taxes Related to Employee Benefit Plans. 

Learn more: EACA FAQs

July 31: File Form 5500 

Unless an extension has been filed, Form 5500 must be filed with the DOL electronically to satisfy the required annual reporting under ERISA. The plan service provider typically prepares the Form 5500 and the employer signs and files the form. 

Note: Human Interest prepares signature-ready Form 5500’s for all service levels. Depending on the level of service you select with Human Interest, we may sign and file the form for you.

If you need to request an extension, file Form 5558 by this date. Human Interest will file the extension request for our clients, as needed.

July 31: File Form 8955-SSA 

Unless an extension has been filed for the Form 5500, 8955-SSA must be filed with the IRS to report plan participants separated from service with a balance for reporting benefits due at retirement age.

August 15: Deadline for Q2 participant statements

Employers must send current year second-quarter statements to participants by this date.

September 1: Safe harbor notices for startup plans

Employers must send notices to participants for startup safe harbor match plans that are effective October 1 of the current year. (New plans must have a minimum of three months of deferrals to contain a safe harbor provision.)

September 15: Extended contribution deadline for S Corps and LLCs taxed as partnerships 

This is the extended deadline for employers to deposit employer contributions and receive a tax deduction for the tax year.

September 30: Distribute Summary Annual Report (SAR) to plan participants

The SAR is a narrative summary of the plan’s financial status and summarizes the information on the plan’s annual report (i.e., the Form 5500). Plans that file a Form 5558 to extend their 5500 filing also extend their SAR due date by two-and-a-half months.

October 1: Review RMDs

Many plan sponsors have work to do in advance of the RMD year-end deadline, such as reviewing the list of affected participants. That’s why it’s a recommendation (not a requirement) for employers to review if participants must take RMDs a few months before December 31.

October 1: Launch a startup safe harbor 401(k) plan

For the first year of a startup safe harbor plan, the safe harbor plan—and the opportunity for participants to make elective deferrals—must be in effect for a minimum of three months (which explains the October 1 deadline to launch).

October 15: Extended Form 5500, Form 8955-SSA; tax deadlines for C corporations, sole proprietorships, LLCs taxed as corporations and single-member LLCs 

This is the extended deadline for filing Form 5500 (where a Form 5558 extension was filed and no other extensions apply).

This is the deadline for C corporations, sole proprietorships, LLCs taxed as corporations, and single-member LLCs to file tax returns with the IRS. It’s also the deadline for these entities to deposit employer contributions and receive a tax deduction for the tax year.

Early November: Plan ahead for required December 1 notices

To meet the upcoming December 1 deadlines for employee notices applicable to the next plan year, it’s wise to take the following proactive actions:

  • If you have an existing safe harbor plan: If you’d like to change the type of safe harbor (example: safe harbor enhanced match → safe harbor non-elective), this must be decided before December 1, so notices can be distributed by then.

  • If you have an existing 401(k) plan that’s not safe harbor: To amend your IRS plan documents to enact a safe harbor match design 401(k) plan for the following calendar year, you must let your provider know prior to December 1.

Other required upcoming notices include qualified default investment alternative (QDIA) and automatic contribution arrangement notices. For administrative ease, a combined notice may be provided.

November 15: Deadline for Q3 participant statements

This is the deadline for employers to send current year quarter three statements to participants.

December 1: Issue safe harbor plan notices for the following year

This is the date when all safe harbor match design plans — both new and old — must have distributed a notice to eligible participants. The notice must be distributed at least 30 days (but no more than 90 days) before the first day of the year.

December 15: Distribute Summary Annual Report (Extended)

This is the deadline employers need to distribute the Summary Annual Report (SAR) to eligible employees if the employer filed an extension via Form 5558.

December 31: Important 401(k) must-do items before year-end

  • Correct a failed ADP/ACP test for the prior year.

  • Set up a qualified retirement plan for the following year. Remember that you can’t have retroactive elective deferrals!

  • Distribute current year RMDs.

  • Last day to sign a plan document amendment if you wish to convert an existing 401(k) plan to a safe harbor match design for the next plan year (or vice versa).

  • Last day to sign a plan document amendment to change your testing method to current year for ACP testing if you currently use the prior year (optional—discuss with your plan service provider)

  • Last day to sign a plan document amendment for any other discretionary change that was effective during the plan year.

  • Ensure your participant fee disclosures required under 404(a)(5) are distributed annually.

401(k) deadlines for employees

January

February

April

May

August

November

December


January 1: Start contributing towards the current year’s limit

If you’re eligible to participate, this is the first day you can start contributing to your 401(k) for the current year. The sooner you start, the more you can spread out your 401(k) contributions across your paychecks (as opposed to attempting to max out with just a few paychecks left in the year). If your employer offers a match, starting sooner can help ensure you receive the maximum benefit of their contribution.

See this IRS article for current and prior year maximum deferral limits.

YearUnder age 50Age 50 or older
2023$22,500$30,000
2022$20,500$27,000
2021$19,500$26,000

January 31: Receive Form 1099-R

Deadline for receiving Form 1099-R if you received distributions during the previous year. Learn more: About Form 1099-R.

February 15: Deadline for Q4 statements

This is the deadline for your employer to send out the prior year's fourth quarter (prior year) statements to participants.

April 1: Your first RMD

A RMD refers to the minimum amount of money you must withdraw from tax-deferred plans like 401(k)s. You’re required to take an annual withdrawal starting with the year you turn 73 (subject to certain exceptions). RMDs are usually calculated by dividing account balances as of 12/31 from the previous year by a distribution factor from the IRS’s Uniform Lifetime Table. Learn more by using this calculator

RMDs must be taken by 12/31. However, if it’s the first year you’re required to take an RMD, you may wait until 4/1 of the following year to withdraw funds (although RMDs in subsequent years must be taken by 12/31). Please consult your tax advisor to determine your best option.

April 15: File federal taxes; deadline for refund of 402(g) excess deferrals

Tax Day is generally April 15, meaning that individual income tax is due. In a typical year, you can apply for a two-month extension for filing your individual taxes (although interest may apply).

This day is also the deadline for refunding excess deferrals to any qualified plan that you deferred into in the prior year without being double taxed on the excess. If you exceed the total 402(g) deferral limit through contributions you made to one or more plans, you should request a refund from one of your plan administrator(s) in advance of this date.  

See this IRS article for current year maximum deferral limits.

May 15: Deadline for Q1 statements

This is the deadline for your employer to send the current year first quarter statements to participants.

August 14: Deadline for Q2 statements

This is the deadline for your employer to send the current year second quarter statements to participants.

November 15: Deadline for Q3 participant statements

This is the deadline for your employer to send out current year quarter three statements to participants.

December 1: Receive plan notices for the following year

This is the date when all safe harbor match design plans — both new and old — must have distributed a notice to eligible participants. The notice must be distributed at least 30 days (but no more than 90 days) before the first day of the year. 

Participant notices may also be provided for Qualified Default Investment Alternatives and/or automatic enrollment and increases in your plan.

December 31: RMD deadline

If applicable, the last day to take RMDs from 401(k) plans is on the last day of the year.

Additionally, you should complete some important 401(k) items before year-end:

  • Ensure any personal changes to your name or address are communicated to your employer.

  • Update or add your beneficiary on file for the plan

Start a 401(k) with Human Interest

A Human Interest 401(k) plan can connect directly with your favorite payroll provider and has zero transaction fees.

Vicki Waun, QPA, QKC, QKA, CMFC, CRPS, CEBS, is a Senior Legal Product Analyst at Human Interest and has over 20 years experience with recordkeeping qualified plans, along with extensive experience in compliance testing. She earned her BSBA in Accounting from Old Dominion University and is a member of ASPPA.

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