S-Corp Mileage Reimbursement: The 2026 Rate Change
The IRS raised its business mileage rate mid-year, from 72.5 cents to 76 cents per mile, effective July 1, 2026. If your S-corp mileage reimbursement policy hasn’t caught up, you’re either underpaying yourself for the second half of the year or setting up a compliance problem the moment you try to true it up. Here’s what actually changed, why it matters more for an S-corp owner-employee than for a typical W-2 worker, and how to update your reimbursement rate without turning part of it into taxable wages.
What the IRS Actually Changed on July 1
The IRS set the 2026 business standard mileage rate at 72.5 cents per mile back in December, effective January 1. That rate lasted exactly six months. In Announcement 2026-11, published in Internal Revenue Bulletin 2026-29, the IRS raised the business rate to 76 cents per mile effective July 1, 2026. The medical and moving mileage rate moved with it, from 20.5 cents to 23.5 cents per mile. The charitable mileage rate stayed at 14 cents per mile, because that figure is fixed by statute rather than adjusted for cost data the way the business and medical rates are.
A mid-year adjustment is unusual. The IRS normally sets one rate for the full calendar year and leaves it alone. The last time it moved the business rate mid-year was 2022. Outside of that, this kind of change simply doesn’t happen, which is exactly why most small-business mileage reimbursement policies aren’t built to handle it.
Why You Can’t Just Deduct the Difference Personally
As the owner of an S-corp, you’re a W-2 employee of your own company. If you drive your personal vehicle for company business and the corporation doesn’t reimburse you for it, that expense doesn’t quietly show up as a deduction on your personal return later. The One Big Beautiful Bill Act permanently closed that door. OBBBA (Public Law 119-21) struck the sunset date on the suspension of miscellaneous itemized deductions under IRC Section 67(h), which covers unreimbursed employee business expenses. That suspension was originally supposed to expire after 2025. It no longer expires at all.
Practically, that means S-corp mileage reimbursement isn’t a nice-to-have administrative detail. It’s the only route to actually capturing the deduction. Miles you drive for the business and never get reimbursed for are simply gone — not deferred, not recoverable on Schedule A, gone.
How S-Corp Mileage Reimbursement Has to Be Structured
To reimburse mileage tax-free, the payment has to come through an accountable plan, governed by Treasury Regulation 1.62-2. Three requirements have to be met. Business connection means the reimbursement only covers expenses actually connected to company business. Substantiation means you document the time, place or use, and business purpose of each trip — a running mileage log, not a reconstructed estimate at year-end. Return of excess means any amount reimbursed above what was substantiated gets paid back to the company.
There’s a useful shortcut built into this: if the company reimburses at or below the IRS standard mileage rate for miles you’ve logged, that reimbursement is automatically treated as substantiated — no need to track actual gas, insurance, and maintenance costs. Reimburse above the standard rate, though, and the excess is treated as paid under a nonaccountable plan. It becomes wages, reported on your W-2, subject to income tax withholding and payroll tax. That’s the mechanism that makes getting the rate right matter — reimbursing too little just costs you money, but reimbursing too much at the wrong rate creates a payroll problem.
Which Rate Applies to Which Miles
The two 2026 rates don’t blend into some average for the year. Based on how the IRS handled its 2022 mid-year change, the earlier rate governs miles driven in the earlier period and the new rate governs miles driven after the change takes effect. For 2026, that means 72.5 cents per mile for business miles driven January 1 through June 30, and 76 cents per mile for business miles driven July 1 through December 31. If your mileage log tracks dates, applying the split is straightforward. If it doesn’t, this is the year to fix that.
Updating Your Accountable Plan Without Blowing the Safe Harbor
Nothing has to be filed with the IRS to adopt the new rate — you just need your internal reimbursement policy and payroll process to reflect it going forward. Keep the mileage log current. Each entry should show the date, miles driven, and business purpose; retrofitting six months of trips from memory in December is exactly the kind of substantiation gap that turns a reimbursement into wages under audit.
Timing matters too. Treasury Regulation 1.62-2 provides a fixed safe harbor: an advance is timely if it’s made within 30 days of the expense, substantiation is timely within 60 days after the expense, and any excess reimbursement is timely returned within 120 days. Staying inside those windows is what keeps the arrangement classified as an accountable plan rather than something the IRS can recharacterize as ordinary wages.
The Mechanical Part Is Easy. The Judgment Calls Aren’t.
Updating a per-mile number is simple. What gets complicated is everything around it — whether it makes more sense for your S-corp to reimburse at the standard rate or use the actual expense method, how a company-owned vehicle should be handled differently than your personal car, and how mileage reimbursement interacts with the rest of your OBBBA planning for the year. Those are facts-and-circumstances questions, not a rate table. If you want a second set of eyes on how your accountable plan is actually documented, contact us and we’ll walk through it with you.