How to Make a Massachusetts PTE Excise Election: Form 63D-ELT and the 90% Credit

Picture a Boston consulting firm organized as an S corporation. It expects $500,000 of Massachusetts income this year, all of it flowing to a single resident shareholder. The shareholder is already at the federal SALT cap from property taxes on the house, so the state income tax she pays on that $500,000 buys her nothing on her federal return. She has until the return due date to decide whether the company should pay Massachusetts tax itself under Chapter 63D. The owner and the numbers below are theoretical, not an actual EntityIQ client, but the decision is one every profitable Massachusetts pass-through faces each year.

What the Chapter 63D excise is

The Massachusetts pass-through entity excise is levied at 5%, the same as the base Part B rate that individuals pay under Chapter 62. It applies to the amount of the entity's income that would be subject to the Massachusetts personal income tax at the partner, shareholder, or beneficiary level. The excise has been available for tax years beginning on or after January 1, 2021, and the Department of Revenue laid out the mechanics in TIR 22-6.

The point of the whole exercise is the federal deduction. Since the Tax Cuts and Jobs Act, an individual can deduct at most a limited amount of state and local taxes under IRC §164(b)(6), a cap the One Big Beautiful Bill Act raised to $40,400 for 2026. Tax the entity pays does not run through that cap. In Notice 2020-75, the IRS confirmed that a partnership or S corporation may deduct these state income taxes in full when computing its non-separately stated income, so the payment reduces the owner's federal taxable income directly rather than sitting behind the SALT cap. That is the same workaround now offered in more than 35 states.

How to make the election

You make the election annually on the entity's timely filed return: Form 3 for a partnership, Form 355S with Schedule S for an S corporation, or Form 2 for a trust. You then confirm the election and pay the excise by filing Form 63D-ELT electronically through MassTaxConnect on or before the return due date, including valid extensions. For a calendar-year S corporation or partnership that is generally March 15, and for a Form 2 fiduciary filer it is generally April 15. The Department of Revenue's guidance requires that both the filing and the payment be made electronically.

Once the election is made for a tax year it is irrevocable for that year and binding on every qualified member of the entity. Individual members cannot opt out. The election is not permanent, though. It is an annual choice, so you decide again each year whether the numbers still favor electing.

The 90% credit, and why it matters

Here is where Massachusetts differs from most states. The entity pays the 5% excise, and then the entity reports each owner's share of that excise on the Massachusetts Schedule K-1. Massachusetts gives each qualified member a refundable credit equal to 90% of that member's distributive share of the excise paid, not 100%. The other 10% is the price of admission. That 10% haircut is real, but for most owners the federal deduction on the full excise payment more than covers it, because the entity deducts 100% of what it paid even though the member is credited for only 90%. The member claims the credit on the personal return, Form 1 for a resident or Form 1-NR/PY for a nonresident, and because the credit is refundable, any amount above the member's Massachusetts tax comes back as a refund.

The math on a $500,000 pass-through

Take the Boston S corporation from the top. All $500,000 flows to one resident shareholder in a 35% federal bracket, and assume she has already used her SALT cap on other taxes, so paying the Massachusetts tax herself gives her no federal deduction. Here is how the two paths compare. The figures are rounded and use 2026 rates.

The lever is the federal deduction, worth $8,750 here because the shareholder sits in the 35% bracket. The 10% credit haircut costs her $2,500, so the net win is $6,250. Notice that the benefit scales with the federal bracket. An owner in the 24% bracket would save only $6,000 federally, and after the same $2,500 haircut the net drops to $3,500. Below roughly the 24% bracket the 10% haircut starts eating a large share of the benefit, which is why the election is a much easier call for high earners than for modest ones.

Estimated payments and the surtax

An electing entity must make estimated tax payments if its required annual payment for the excise is $400 or more, and those payments are due during the year even though the Chapter 63D election itself is not finalized until the return is filed. Missing them can trigger an underpayment penalty on Form M-2210, so a profitable entity should fund the excise on the same quarterly schedule an individual would use. This is the most common way owners stumble. They plan to elect in March but never funded the quarterly payments, and the penalty shaves the benefit.

One more wrinkle for high earners. Massachusetts adds a 4% surtax on personal income above roughly $1.1 million, a threshold indexed each year. The 63D excise is only 5%, matching the base Part B rate, so it does not cover that surtax. An owner over the surtax threshold still pays the 4% at the individual level, and the entity-level credit does not offset it. The workaround shelters the 5%, not the surtax on top.

When the election makes sense

If your Massachusetts pass-through is profitable, your owners are individuals near the top of the federal brackets, and their SALT deductions are already capped, the Chapter 63D election almost always pays for itself. The federal deduction on the full excise beats the 10% credit haircut by a wide margin. The election gets harder to justify when owners are in low federal brackets, when the entity's income is small, or when much of the income belongs to owners the credit cannot help, such as certain corporate or tax-exempt members. Run the numbers on your own facts before the return due date, because once you miss it for the year, you have missed it.

Massachusetts is only one piece of the picture. Whether an S-Corp election makes sense at all still turns on the federal self-employment tax math. You can model that side with the EntityIQ S-Corp tax calculator, then read our broader guide on the PTET deduction and the SALT cap workaround to see how the entity-level tax fits with the rest of your return.

This article is educational and is not legal or tax advice. The numbers above are 2026 figures, and the shareholder is theoretical. Please consult a qualified CPA before making a Chapter 63D election.