A tax status, not a kind of company
You cannot form an S corporation with the Secretary of the Commonwealth. You form a corporation or an LLC under state law, and then the business elects S status with the IRS. The IRS instructions for Form 2553 say a corporation, or another entity eligible to be treated as a corporation, uses the form to make the election, and an eligible LLC that makes it is treated as a corporation from the election's effective date without filing a separate Form 8832.
That is why an LLC and an S corporation are not opposites. A Massachusetts LLC can be taxed as an S corporation while remaining an LLC for legal purposes, with its LLC annual report to the Secretary of the Commonwealth continuing as before.
Who can elect
The IRS lists the tests in the Form 2553 instructions. All of them must be met on the day the election takes effect, and afterwards, or the status can end.
- It is a domestic corporation, or a domestic entity eligible to be treated as a corporation
- It has no more than 100 shareholders; a married couple can count as one, and members of a family can be treated as one shareholder
- It has only one class of stock
- Its shareholders are eligible, which rules out nonresident aliens
- It files Form 2553 in time, or qualifies for late-election relief
How the profit is taxed
An S corporation files Form 1120-S each year and gives each shareholder a Schedule K-1 showing their share of income, deductions and credits. The IRS describes the result simply: the income is generally taxed to the shareholders rather than to the corporation. The owners report their share on their own returns whether or not the cash is taken out.
There are exceptions where the company itself can owe federal tax, such as on certain built-in gains, but for most small service businesses that start as S corporations the profit simply flows through.
Salary plus distributions
This is the part that changes an owner's life. An owner who works in the business is an employee of it. The IRS has said since its 2008 fact sheet on officer pay that S corporations should treat payments for an officer's services as wages, not as distributions. So the owner goes on payroll, with income tax withheld and Social Security and Medicare paid on the salary.
Profit beyond the salary can be paid out as distributions, which are not wages and so carry no Social Security or Medicare tax. That split is where the tax difference from a sole proprietorship comes from. The salary has to be reasonable for the work actually done. The IRS says there are no specific guidelines in the Code or the regulations for what that means, and it lists factors courts use instead, such as your duties, time, training and what comparable businesses pay. There is no percentage rule.
| Sole proprietor or single-member LLC | S corporation owner who works in the business | |
|---|---|---|
| Pay for your work | No salary; you are taxed on all profit | W-2 salary through payroll |
| Social Security and Medicare | Self-employment tax on 92.35% of all profit | 15.3% combined on salary, split between company and owner |
| Remaining profit | Already counted above | Passes through on the K-1; distributions carry no Social Security or Medicare tax |
| Returns | Schedule C and Schedule SE | Form 1120-S plus payroll returns, and your own Form 1040 |
What Massachusetts adds
The Department of Revenue says entities that are S corporations for federal purposes are S corporations for Massachusetts, apart from security corporations. You do not file a separate state election. What you do take on is a state filing and a minimum tax.
Every S corporation files Form 355S, with Schedule S and an SK-1 for each shareholder, due on the 15th day of the third month after year end and filed electronically. The corporate excise has a non-income measure of $2.60 per $1,000 of taxable Massachusetts tangible property or net worth, and every S corporation pays at least the $456 minimum excise, however small it is. An entity-level tax on income applies only when total receipts reach $6 million (2.00%) or $9 million (3.00%), which does not affect most owner-run businesses.
Owners still pay Massachusetts personal income tax on their share of profit on Form 1. An owner paid through W-2 payroll also counts as part of the business's covered workforce for Massachusetts paid family and medical leave, with an exception for businesses co-owned by family members. The 2026 total rate is 0.88%, and the 2027 rate has not been set yet.
Deadlines to know
| Filing | Rule | Next date |
|---|---|---|
| Form 2553, election for 2027 | No more than 2 months and 15 days after the start of the tax year, or any time in the prior year | 15 March 2027 |
| Form 1120-S, tax year 2026 | 15th day of the third month after year end (2025 returns were due 16 March 2026 because the 15th was a Sunday) | 15 March 2027 |
| Form 355S, tax year 2026 | 15th day of the third month after year end; automatic 6-month extension if payment requirements are met | 15 March 2027 |
The federal late-filing penalty for Form 1120-S is charged per shareholder, per month, for up to 12 months: $255 under the 2025 instructions and $260 for returns required to be filed in 2027.
Is it right for you?
An S corporation makes sense when the payroll tax saved on distributions is larger than everything it adds: payroll, a second tax return, the Massachusetts minimum excise, leave contributions on your salary and a smaller qualified business income deduction. At modest or uneven profit, it often is not. The comparison should be done with your own numbers, not a rule of thumb, and we can run the comparison with your actual numbers.
Before that conversation, it helps to read what an honest savings comparison must include, and to work through our readiness worksheet.
Figures on this page were checked against the IRS and Massachusetts sources listed alongside on 28 Sep 2026. They change — confirm the current amount before relying on one.
General information for owner-led businesses, not advice for your specific situation. Tax and accounting rules change, and how they apply depends on facts particular to your business. Talk to us — or to another qualified professional — before acting on anything here.
