How to Make a Wisconsin PTET Election: Form 5S and the 7.9% Rate (2026)

A Wisconsin general contractor calls me in the fall. His S-corp will clear about $180,000 this year, and a buddy at the lumberyard told him he should be making the "PTET election" to beat the SALT cap. I tell him the filing takes thirty seconds, but for his income it might cost him money, and we should run the numbers before he checks the box. That surprises him, because every article he read made the election sound like free money. In Wisconsin it is one of the few states where a middle-bracket owner can come out behind. The contractor is theoretical, but the trap is real, so here is how the election works in 2026.

What the Wisconsin election is

Wisconsin was early to this. Under 2017 Wisconsin Act 368, signed in December 2017, a tax-option (S) corporation could elect to be taxed at the entity level starting with tax year 2018, and partnerships got the same election beginning in 2019. That put Wisconsin among the very first states to build a workaround to the federal cap on state and local tax deductions. The rule lives in Wis. Stat. §71.365(4m). When the election is made, the S-corp itself pays Wisconsin income tax on the net income reportable to the state, and the shareholders take that same income off their own Wisconsin returns. The entity computes the tax on Schedule 5S-ET, which it files with the corporate return.

How to make the election on Form 5S

You make the election by checking the entity-level tax election box in Part A of Form 5S, the Wisconsin tax-option corporation return, for each year you want it. The election is annual, it applies to the entire taxable year, and it requires the consent of shareholders who together hold more than 50% of the shares on the day the election is made, under Wis. Stat. §71.365(4m). You do not send that consent to the Department of Revenue, but you must keep it in your corporate records, and the election has to be made by the extended due date of the Form 5S. One more piece of housekeeping matters: an electing tax-option corporation has to make quarterly estimated tax payments on the entity-level tax, the same way a C-corporation does, and it computes the tax on Schedule 5S-ET filed with Form 5S. Skip the estimates and the entity can owe underpayment interest even on a timely return.

The federal benefit you are buying

The reason anyone does this is the federal side. Under IRS Notice 2020-75, state income taxes paid at the entity level by an electing pass-through reduce the entity's federal ordinary income and flow through on the K-1, which sidesteps the §164(b)(6) cap that limits an individual's itemized SALT deduction. That cap rose to $40,400 for 2026 under the One Big Beautiful Bill Act, with a phasedown that begins at $505,000 of modified AGI. For an owner whose other state and property taxes already fill that cap, a dollar of Wisconsin income tax paid personally buys nothing federally. The same dollar, paid by the S-corp under the election, is fully deductible. That is the entire pitch, and it is a good one at the right income level, which I cover further in the PTET deduction and SALT cap guide.

The Wisconsin twist: a 7.9% rate on income you would tax lower

Here is what the generic PTET articles leave out. The Wisconsin pass-through entity tax rate is a flat 7.9% of the net income reportable to Wisconsin, set by Wis. Stat. §71.365(4m) at the same rate C-corporations pay. It does not follow the graduated individual brackets, so the same 7.9% applies whether your own marginal rate would have been 3.5% or 7.65%. And that 7.9% is higher than every individual rate in Wisconsin, including the 7.65% top bracket and the 5.3% bracket most owners actually sit in. Wisconsin's individual rates for 2026 still top out at 7.65%, and the 5.3% bracket runs all the way up past $320,000 of taxable income, per the Department of Revenue rate tables. So when the entity pays 7.9% on income you would have taxed at 5.3%, you prepay an extra 2.6 cents of Wisconsin tax on every dollar, and the federal deduction has to be worth more than that premium for the election to pay off. There is no reconciliation back to your bracket. The 7.9% is final.

What you give up as a shareholder

The exclusion cuts both ways. Once the election is made, shareholders may not include their proportionate share of the S-corporation's income, gain, loss, or deduction in their Wisconsin adjusted gross income. The entity reports and pays the tax, and the income simply drops off the shareholder's Wisconsin return. That is convenient for a nonresident owner, who no longer has a Wisconsin filing obligation, but it removes several things a resident might have used. Most of the corporation's Wisconsin tax credits, other than the credit for tax paid to another state, can no longer be claimed by the entity and instead pass through to shareholders, which can strand a credit if the shareholder has little other Wisconsin income. A resident shareholder also cannot claim a credit for taxes paid to another state on income that is no longer on the Wisconsin return, because there is nothing left to credit against. And if the business runs a loss, that loss stays at the entity level for the electing year instead of flowing to your personal return. The Department of Revenue lays out these effects in its Publication 102 on tax-option corporations.

When the Wisconsin election makes sense

The election is a clear winner for owners who are both in the top 7.65% bracket and above the federal SALT cap, which describes most of the six-figure and seven-figure S-corp owners I work with in the state. For them the tiny rate premium over 7.65% is trivial next to a full federal deduction they could not otherwise get. It is a much closer call, and often a loser, for an owner sitting in the 5.3% bracket, especially one who is still under the $40,400 SALT cap and would have deducted the Wisconsin tax anyway. So do not copy what the guy at the lumberyard did. Weigh the 7.9% flat rate against your own bracket, and confirm the federal deduction more than covers the premium before you check the box. If you also have income in a neighboring state, read the Minnesota PTET election guide and the broader SALT cap after OBBBA piece too.

If you have not settled whether an S-corp election even pays for your income level, start there before you worry about the state layer. Run the numbers in the EntityIQ S-Corp tax calculator, and if the election makes sense it will generate a pre-filled Form 2553. The Wisconsin entity-level election only matters once you are an S-corp and your SALT cap is a live constraint.

This article is educational and is not legal or tax advice. The owners described are theoretical, and the figures are 2026 estimates that stack the pass-through income at the stated marginal rate. Please consult a Wisconsin CPA or enrolled agent before making the election.