Form 5500 Filing for Multi-Employer Plans: What’s New in 2025 — And How to File It Directly from Your Software

Union.dev is now an approved EFAST2 e-remitter. Here’s why that matters.

Form 5500 filing season is coming — and 2025 brings some important changes for multi-employer plans.

Whether you're managing Taft-Hartley funds in the U.S. or DB pension plans across multiple employers, this year’s filing cycle has more complexity, more scrutiny, and more urgency than ever. The good news? For the first time, you can manage everything — from data intake to filing submission — directly in Pension OS.

Union.dev is now an approved electronic remitter (e-remitter) for EFAST2, which means TPAs and fund administrators can file Form 5500s directly from our software. No third-party file upload tools. No external XML generators. No missed deadlines because a remitter was too busy.

In this post, we’ll break down:

What’s new for Form 5500 filings in 2025
Why multi-employer plan filings are uniquely painful
What EFAST2 is (and why most systems aren’t built for it)
How Pension OS simplifies — and now submits — Form 5500s for you

Quick Refresher: What Is Form 5500, and Who Needs to File It?

The Form 5500 is an annual reporting requirement for pension and welfare benefit plans under ERISA. It’s how the IRS and DOL ensure transparency, accuracy, and proper management of plan assets.

If you administer a multi-employer defined benefit plan, you’re required to file a Form 5500 every year. And it’s not just one form — you may also need to file:

Schedule MB (actuarial info for DB plans)
Schedule R (retirement plan info)
Schedule A or C (service provider disclosures)

For multi-employer plans, this filing is complicated by:

Numerous contributing employers
Varying eligibility and accrual structures
Difficult-to-aggregate plan-level and employer-level data
High stakes for accuracy and timeliness

What’s New for Form 5500 Filings in 2025?

This year, the DOL and IRS have introduced several updates you need to know:

Schedule MB actuarial changes
Revised reporting on assumptions, funding status, and risk metrics.
Increased focus on employer-level data
Especially for multi-employer DB plans — greater detail is now expected.
Stricter EFAST2 formatting requirements
XML validations are more rigorous, and manual errors are harder to ignore.
Audit risk rising
The DOL is increasing its use of electronic data audits, especially on late or inconsistent filings.

And while the form changes matter, what’s really stressing TPAs is the technical process — getting everything validated, formatted, and filed correctly using EFAST2.

What Is EFAST2 — and Why Is It So Frustrating?

EFAST2 is the Department of Labor’s system for receiving and processing Form 5500 filings. It’s how you transmit completed forms electronically.

Sounds simple, right? It’s not.

Most TPAs still rely on outdated filing workflows, which include:

Exporting data manually
Creating XML files via a third-party tool
Sending that file to a registered e-remitter
Waiting for status confirmation from a separate system

Each step adds delay, risk, and cost — and it only takes one formatting or validation error to derail the process.

Pension OS Is Now EFAST2-Ready — End-to-End

Union.dev is now officially approved as an EFAST2 electronic remitter, which means you can complete your entire Form 5500 process inside Pension OS. No manual handoffs. No XML exports. No third-party remitter tools.

What’s Built In:

Automatic EFAST2 formatting + validation
Secure API submission directly to DOL
Live filing status + confirmation tracking
Digital sign-off workflows for trustees, actuaries, and admins
One-click export of all required schedules and attachments
Permanent archive of all submitted forms and metadata

“You don’t just prep your 5500s in Pension OS — you file them.”

Why This Matters for Multi-Employer Plans

Multi-employer DB plans are some of the most complex filings in the system. That’s exactly why you need an admin platform that can handle:

Data from multiple employers (with different remittance patterns)
Varying plan rules and eligibility logic
Flexible contribution structures
Cross-checked totals from actuarial, financial, and operational data
Audit trails that can be validated quickly if the DOL comes knocking

Without automation, this process takes weeks. With Pension OS, it can take hours.

Case Study: Turning Weeks into Clicks

One of our clients — a U.S.-based TPA managing 70+ Taft-Hartley plans — used to spend 2–3 weeks gathering, validating, and exporting data for Form 5500s each year. Their team depended on a separate XML vendor for formatting, and still had to manually track down errors before filing.

After switching to Pension OS: