Benefits Reconciliation: Finding the Overpayments Already Hiding in Your Payroll
Your benefits data lives in three systems that don't always agree. Here's where the money leaks, and what a real reconciliation checks.
By Acceler8 Global Team
Health benefits are now one of the largest line items an employer carries. And most companies never check the bill.
The average family plan cost $26,993 a year in 2025, according to the KFF Employer Health Benefits Survey. Single coverage cost $9,325. The employer paid most of both.
And it's rising. Mercer projects a 6.7% increase for 2026, a fifteen-year high, taking average cost above $18,500 per employee.
When a number that size moves that fast, small billing errors stop being small.
The three-system problem
Benefits data lives in three places. They rarely agree.
Most companies check payroll against the carrier bill, or HRIS against payroll. Almost nobody checks all three.
That gap is where the money sits.
Where the money actually leaks
Four causes come up again and again.
The first one is the big one. An employee leaves. HR processes it. Payroll stops the deduction. But nobody tells the carrier, or the carrier processes it a month late.
You keep paying their premium. Sometimes for months.
Analysis of employer–carrier billing disputes puts the average discrepancy above $7 per employee per month, with individual cases ranging from 34 cents to $19.
At $7 per employee per month, a 500-person company is leaking around $42,000 a year. Nobody notices, because it never appears as a line item. It just makes the invoice slightly wrong, every month.
A word about the vendor numbers
You will find plenty of impressive statistics about benefits audits. Almost all of them come from companies that sell benefits audits.
Dependent eligibility audit findings are usually quoted at 3–5% or 3–10% of dependents being ineligible. Both figures come from audit vendors describing their own client results. There is no independent, large-sample study.
That doesn't mean the problem isn't real. It means you should run your own numbers before believing a projected saving.
The COBRA clock
COBRA creates its own reconciliation gap, because the deadlines are long and they run in sequence.
Add it up. Someone can elect on day 59 and pay on day 104. Until then they sit on your carrier bill with no premium against them.
That's not an error. It's how COBRA works. But if your reconciliation flags them as an overpayment, you'll chase a ghost, and if it ignores them entirely, you'll miss the ones who never pay at all.
The 2026 numbers your reconciliation should check against
| ITEM | 2026 LIMIT |
|---|---|
| HSA contribution, self-only | $4,400 |
| HSA contribution, family | $8,750 |
| HDHP minimum deductible, self-only / family | $1,700 / $3,400 |
| HDHP out-of-pocket maximum, self-only / family | $8,500 / $17,000 |
| Health FSA salary reduction limit | $3,400 |
| Health FSA carryover | $680 |
| Dependent Care FSA | $7,500 |
| 401(k) elective deferral | $24,500 |
| 401(k) catch-up, age 50+ | $8,000 |
| 401(k) catch-up, ages 60–63 | $11,250 |
IRS Notice 2026-05 (HSA/HDHP), Rev. Proc. 2025-32 (FSA), IRS Notice 2025-67 (retirement plans). The Dependent Care FSA limit rose from $5,000 and was made permanent by the One Big Beautiful Bill Act.
The Dependent Care FSA jump is the one to watch. It went from $5,000 to $7,500, a 50% increase. If your payroll system still caps at the old limit, employees who elected more will be under-deducted all year.
What a real reconciliation checks
Where to start
Pull one month's carrier bill and one month's payroll register. Match them line by line.
You are not looking for a clean result. You are looking for the size of the gap. That number tells you whether this is a quarterly check or a monthly one.
Sources
1. KFF. 2025 Employer Health Benefits Survey. https://www.kff.org/health-costs/2025-employer-health-benefits-survey/
2. Mercer. Health benefit cost expected to exceed $18,500 per employee in 2026 (n=2,010 employers). https://www.mercer.com/en-us/about/newsroom/employers-and-workers-face-affordability-crunch-as-health-insurnace-cost-is-expected-to-exceed-18500-per-employee-in-2026/
3. US Department of Labor. COBRA Continuation Health Coverage FAQ. https://www.dol.gov/agencies/ebsa/about-ebsa/our-activities/resource-center/faqs/cobra-continuation-health-coverage-workers
4. Internal Revenue Service. Notice 2026-05, HSA and HDHP limits for 2026. https://www.irs.gov/pub/irs-drop/n-26-05.pdf
5. Internal Revenue Service. Notice 2025-67, retirement plan limits for 2026. https://www.irs.gov/pub/irs-drop/n-25-67.pdf
Dependent eligibility and benefits-audit recovery statistics circulating in the market come from audit vendors describing their own client results. No independent large-sample study exists. Run your own baseline before relying on any projected saving.
Keep reading
Off-Cycle Payroll Runs: When They're Worth It and When They're a Symptom
Sometimes an off-cycle run is exactly the right tool. Sometimes it's a sign your regular payroll isn't catching errors before they go out.
Read articlePayroll & HRMulti-State Payroll: What Actually Changes When You Hire Across State Lines
One remote hire in a new state can trigger four separate registrations, a new tax rate, and a paid leave programme you'd never heard of.
Read articlePayroll & HRUS Payroll 101: How It Works, What It Costs, and When to Outsource It
A plain-English walk through what payroll involves, how to think about paying people fairly, and when it makes sense to hand the whole process to someone else.
Read article