The Deal You Never Agreed To
Your fully-insured carrier collected premiums all year. Your employees stayed healthy. Claims ran light. So where did the difference go?
The carrier kept it. Every dollar of surplus between what you paid and what they paid out belongs to them, not you. According to PBMs Explained: Self-Funded vs. Fully Insured Health Plans, if actual claims are lower than the premium collected, the insurer keeps the surplus and the employer receives nothing back.
That's the arrangement. You take on no upside. The carrier takes all of it.
Predictable Premiums Don't Mean Predictable Costs
The pitch for fully-insured coverage is simplicity. Pay a fixed premium, transfer the risk, sleep at night. But the simplicity comes with a catch.
Carriers set premiums based on firm size, demographics, and claims history. They assume the risk on bad years. But on good years, they book the margin as profit. Then they hand you a renewal increase anyway.
As The Hidden Costs of Fully Insured Plans points out, renewals still increase year over year even when actual claims fall below projections. Risk margins and administrative costs are rarely refunded or reduced. So the "predictability" you're paying for isn't really predictability. It's a one-sided risk transfer dressed up as simplicity.
What Self-Funding Actually Changes
When you self-fund, the math flips. If claims run under budget, the surplus stays in your plan. You own it.
You can roll it forward, redeploy it, or use it to fund benefits that cost employees nothing at the point of care. That's not theory. 2025: The Great Employer Exodus from Fully Insured Health Plans documents a municipality client that was facing a 33% fully-insured renewal increase.
They switched strategies and reduced the effective increase to 8% net, saving $539,000 in year one. That $539,000 was redirected to fund $0 primary care visits through a new clinic. A renewal increase became a benefit enhancement.
There are structural cost advantages too. PBMs Explained notes that fully-insured plans carry cost layers that self-funded plans avoid or reduce. Those include state insurance mandates, community rating rules, and insurance premium taxes. ERISA preemption eliminates most of that overhead for self-funded employers.
Why CFOs Should Care Right Now
Every year you stay fully insured with favorable claims, you're subsidizing your carrier's margin. The surplus doesn't disappear. It just gets booked somewhere you can't see.
| Scenario | Fully-Insured | Self-Funded |
|---|---|---|
| Claims under budget | Carrier keeps surplus | Employer keeps surplus |
| Renewal after good year | Increase likely | Savings rollover |
| State premium taxes | ✓ Applied | ✗ Avoided |
| State mandates | ✓ Applied | ✗ Avoided (ERISA) |
| Cost transparency | Low | High |
| Surplus ownership | Carrier | Employer |
Self-funding converts retained carrier margin into a plan asset your CFO controls. That's cash you can deploy toward stop-loss coverage, a direct primary care clinic, or a claims reserve. Anything that actually serves your employees.
The carrier owns the entire supply chain under a fully-insured arrangement, including medical and pharmacy. As The Alliance notes, that lack of transparency limits an employer's ability to identify cost drivers or develop effective cost-containment strategies. One lever, once a year, after the surplus is already gone.
The Real Question
Self-funding isn't the right fit for every employer. Claim volatility, employee demographics, and cash flow all matter. But if your claims have run favorably for two or three consecutive years, you should be asking one simple question.
How much did your carrier keep, and what did you get in return?