Short answer: Two separate compliance deadlines land on Oct. 15, 2026. Employers with group health plans that include prescription drug coverage must send Medicare Part D creditable coverage notices. Separately, employers with calendar-year benefit plans who filed for a Form 5500 extension must file by that date. 

They’re unrelated requirements that happen to share a date, so it’s worth checking whether one, both, or neither applies to you. 

Who does the Oct. 15 deadline apply to? 

• Part D notices apply to any employer with a group health plan that provides prescription drug coverage. 

• Form 5500 extensions apply to any employer with a calendar-year employee benefit plan that filed IRS Form 5558 for an extension. 

Medicare Part D notices 

If your group health plan includes prescription drug coverage, you have to tell Medicare Part D-eligible individuals, before Oct. 15 each year, whether that coverage is at least as good as Medicare Part D. That’s what “creditable coverage” means. 

This matters to your people. Someone without creditable drug coverage who doesn’t enroll in Part D when they’re first eligible will likely pay higher premiums if they enroll later. 

What happens if you don’t send the notice? 

There’s no specific penalty attached to the Part D notice requirement. But skipping it can damage employee relations, especially if someone gets hit with a late enrollment penalty because they didn’t know their coverage wasn’t creditable. Employers claiming the Retiree Drug Subsidy also won’t qualify for it without these notices, and other federal laws can create indirect consequences. 

Extended Form 5500 filings 

Employers subject to the Employee Retirement Income Security Act of 1974 (ERISA) have to file an annual report, Form 5500, electronically for each benefit plan they maintain, unless an exemption applies. 

Calendar-year plans owed their 2025 reports to the U.S. Department of Labor (DOL) by July 31, 2026. If you filed IRS Form 5558 by that date, you got an automatic, one-time 2.5-month extension, which puts your deadline at Oct. 15, 2026. 

One exemption worth knowing: small welfare benefit plans with fewer than 100 covered participants that are unfunded, fully insured, or a combination of the two don’t have to file Form 5500 at all. 

What are the penalties for a late Form 5500? 

Under ERISA, the DOL can assess up to $2,739 per day for every day a plan administrator fails or refuses to file a complete Form 5500. Penalties can be waived for reasonable cause, and plan administrators who use the Delinquent Filer Voluntary Compliance Program may avoid the steeper assessments. 

Action steps 

• Confirm whether your health plan’s prescription drug coverage is creditable or noncreditable, then send your Medicare Part D disclosure notices before Oct. 15, 2026. 

• If you filed Form 5558 on time, work with your service providers to file Form 5500 electronically, including all required schedules and attachments, through the DOL’s EFAST2 filing system. 

• Check now whether a filing exemption applies to any of your plans, so you’re not preparing a report you don’t owe. 

Frequently asked questions 

When are Medicare Part D notices due in 2026? 

Before Oct. 15, 2026. The deadline repeats before Oct. 15 every year. 

What is creditable prescription drug coverage? 

Coverage that’s at least as good as standard Medicare Part D coverage. 

Is there a penalty for not sending a Part D notice? 

No specific penalty applies to the notice requirement itself, but employers claiming the Retiree Drug Subsidy lose eligibility without it. 

What’s the extended Form 5500 deadline for 2025 plan years? 

Oct. 15, 2026, for calendar-year plans that filed IRS Form 5558 by July 31, 2026. 

How much is the Form 5500 late filing penalty? 

Up to $2,739 per day, though the DOL may waive it for reasonable cause. 

The Bright Side 

Two deadlines landing on the same day is a nuisance, but it’s also a useful forcing function. If you’re already pulling participant counts and plan documents for the Form 5500, you have most of what you need to confirm whether your drug coverage is creditable, and to see which plans are exempt from filing in the first place. 

Daybright helps employers work through that check once instead of twice, and keeps the rest of the compliance calendar from sneaking up, through one partner for Employee Benefits, Retirement, Compliance, and Individual Financial Planning. 

Not sure whether the Oct. 15 deadline applies to your plans? Contact us at daybright.com/contact. 

Source: Adapted from Zywave content.

This post is not intended to be exhaustive nor should any discussion or opinions be construed as legal advice. Readers should contact legal counsel for legal advice. Content sourced from Zywave.

• Category: News
• Tag: Compliance, Employee Benefits