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Important 401(k) Compliance Dates and Deadlines

This chart will help you stay informed of important dates and deadlines associated with your 401(k) plan.

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This chart will help you stay informed of important dates and deadlines associated with your 401(k) plan.

While many of these responsibilities are handled by Betterment, as a 401(k) plan sponsor it’s important that you are aware of important dates and deadlines associated with administering your plan.

Date Responsibility Previous Plan Year Current Plan Year
Jan 31 Betterment IRS Forms 1099-R available to participants.  
Feb 10 Betterment Annual Return of Withheld Federal Income Tax (Form 945) due.  
Mar 1 Participant Deadline for employees who participated in multiple plans to notify sponsors of excess deferrals (402(g) excess).  
Mar 15 Betterment Deadline for refunds to participants for failed ADP/ACP tests(s). Failure to meet this deadline could result in a 10% tax penalty for plan sponsors.  
Mar 15 Plan Sponsor Employer contributions (e.g., profit sharing, match, safe harbor) due for deductibility for incorporated entities.¹ Failure to meet this deadline could preclude plan sponsor from tax deductibility. Deadline to establish plan for the prior tax year
Apr 1 Plan Sponsor Deadline to confirm that Initial Required Minimum Distributions (RMDs) were taken by participants who: turned 72 ² before previous year-end; are retired/terminated; and have a balance  
Apr 15 ³ Plan Sponsor Employer contributions (e.g., profit sharing, match, safe harbor) due for deductibility for LLCs, LLPs, sole proprietorships (unincorporated entities).¹ Failure to meet this deadline could preclude plan sponsors from tax deductibility.  
Apr 15 Betterment Deadline to complete corrective distributions for 402(g) excess deferrals.  
Jul 29 ⁴ Plan Sponsor Deadline to distribute Summary of Material Modifications (SMM) to participants (only if plan was amended).  
Jul 31 ³ Betterment ⁴ Deadline to electronically submit Form 5500 (and third-party audit if applicable) OR request an extension (Form 5558).  
Sep 30 Plan Sponsor Deadline to distribute Summary Annual Report (SAR) to participants and beneficiaries (unless Form 5500 extension filed; deadline to distribute will be December 15).  
Oct 1 Plan Sponsor   Deadline to establish a new safe harbor match 401(k) plan.
Oct 15 ³ Plan Sponsor Deadline to electronically submit Form 5500 and third-party audit, if applicable, if granted a Form 5558 extension.  
Dec 1 Plan Sponsor (Notices prepared by Betterment)   Deadline to distribute supplemental safe harbor notice to participants for safe harbor (“maybe”) plans. ⁵
Dec 1 Plan Sponsor (Notices prepared by Betterment)   If applicable, distribute to participants for next plan year: Safe harbor notice, Qualified default investment alternative (QDIA) notice, Automatic enrollment notice
Dec 1 Plan Sponsor (Amendment drafted by Betterment) Deadline to execute amendment to make a traditional plan any type of safe harbor plan (match or nonelective). Deadline to execute amendment to make a traditional plan a safe harbor match plan for following plan year
Dec 15 Plan Sponsor (SAR prepared by Betterment) Deadline to distribute Summary Annual Report (SAR) to participants, if granted a Form 5558 extension.  
Dec 31 Plan Sponsor Deadline to make safe harbor and other fixed employer contributions. Deadline for Annual Required Minimum Distributions (RMDs). Art
Dec 31 Plan Sponsor   Deadline to execute amendment to make traditional plan a 3% safe harbor nonelective plan for the current plan year

¹ Assumes calendar tax year. Additionally, if your company files a tax extension, you have until the extension deadline to fund the contributions.

² This was increased from 70½ in 2019 and earlier years.

³ Or first business day thereafter.

⁴ 210 days after the year end of the effective amended date, which is July 28 in leap years.

⁵ Safe harbor “maybe” Plans (specified in the plan document) are able to adopt a safe harbor nonelective plan 30 days before the end of the plan year. Please review your plan document to confirm if the plan has adopted such a provision.