Benefits Enrollment Deadlines: What Employers Can’t Afford to Miss

When you’re running a business, benefits deadlines can sneak up fast—and missing them can mean frustrated employees, compliance penalties, or costly administrative messes.

Whether you’re offering health benefits for the first time or just trying to keep track of the annual enrollment cycle, this article is your go-to calendar for what needs to happen when—so nothing slips through the cracks.

Let’s break it down month-by-month, highlight what applies to your business size, and give you clear next steps to stay ahead.

Benefits Timeline Overview for Small Businesses

January

• Form W-2 due to employees – If you offer group health insurance, W-2s must report total cost of coverage (Box 12, Code DD) for businesses with 250 or more employees.
  
  
• Form 1095-B/1095-C due to employees – If you’re an Applicable Large Employer (ALE) with 50 or more FTEs, this must be distributed by January 31 (extensions may apply).

February

• Form 1094-B/1094-C due to IRS – Paper filers must send ACA transmittals to the IRS by February 28.

March

• E-filing deadline for 1094/1095 forms – If you're filing electronically, the deadline is March 31.

April

• Wrap up prior year reporting – Finalize compliance documents such as COBRA notices, Summary Plan Descriptions (SPDs), and ACA filings.

Mid-Year: Key Reminders & Open Enrollment Prep

June

• Start planning Open Enrollment (OE) – Especially if your plan renews January 1. This is the time to review existing offerings, collect employee feedback, and meet with your broker or provider.

July

• Form 5500 due – If you have 100 or more plan participants in an ERISA-covered plan (health insurance, FSA, HRA, or retirement), this must be filed by July 31 unless you request an extension.

Fall: Open Enrollment Season

September

• Distribute Open Enrollment materials – This allows employees time to review benefits, ask questions, and make decisions.
  
  
• Medicare Part D Notices – Must be sent to Medicare-eligible employees by October 15.

October

• Finalize plan details and rate changes – Share what’s new or changing and give your team time to prepare.
  
  
• Begin Open Enrollment – Most companies launch enrollment in mid-October to give employees a few weeks to review and choose benefits.
  
  

November

• Close Open Enrollment – Aim to finish by mid-November so changes can be processed in time for January 1.
  
  
• Send deduction updates to payroll – Ensure employee elections are accurately reflected in payroll deductions.

Year-End Wrap-Up

December

• Double-check enrollments – Confirm all employees are enrolled in the correct plans.
  
  
• Issue Summary of Benefits and Coverage (SBC) – Required at renewal or when employees make new elections.
  
  
• Prep for ACA reporting – Start evaluating employee hours and full-time status under ACA guidelines.
  
  

What Employers Often Miss (And How to Avoid It)

1. COBRA Notices

Missed COBRA notices can result in daily penalties up to $200 per employee. Automate this process with a benefits administrator or ensure your provider handles it.

2. Late Form 5500s

This form carries significant penalties if missed—up to $250 per day. If you’re unsure whether it applies to you, ask your broker or payroll provider.

3. Confusing Open Enrollment Windows

Poor communication leads to rushed decisions and frustrated employees. A simple Open Enrollment schedule with email reminders, one-pagers, and meetings can make a big difference.

Tools That Can Help You Stay on Track

If you're still managing benefits manually or using outdated systems, you're at risk for errors and delays.

Modern solutions like Cadence can simplify:

• Enrollment windows and automatic reminders
  
  
• ACA and IRS compliance reporting
  
  
• Payroll integration and deduction syncing
  
  
• Carrier file submissions
  
  
• COBRA and 5500 filing support
  
  

One platform. Fewer headaches.

Final Thoughts: Don’t Let Deadlines Derail Your Year

Missing a benefits deadline is more than an administrative error—it can impact employee trust and expose your business to costly compliance issues. But with a clear calendar, consistent communication, and the right partner, you can stay ahead and stress-free.