The $100K rule is the wrong test for an S-corp election

You have probably heard the rule: once your profit hits $100,000, you should become an S corporation. It is the most repeated piece of advice in small business tax, and it is the wrong test. We have seen owners well past $100,000 for whom an S-corp made no sense, and owners nowhere near it for whom it made a great deal of sense.

The number that decides it is not your profit. It is the gap between your profit and what your own work is actually worth.

What people mean by S-corp tax savings

An S corporation gives you two ways to take money out of the business. The first is as its employee: you run payroll, pay yourself a W-2 wage, and that wage carries payroll taxes. The second is as its owner, through a distribution of profit, which does not carry self-employment tax.

That gap is the whole of what most people mean by S-corp savings. Self-employment tax runs at 15.3% - 12.4% for Social Security and 2.9% for Medicare (IRS, Self-Employment Tax). Every dollar that legitimately does not have to be wages is a dollar that steps around it.

Which is why the real question is never whether profit crossed $100,000. It is how much of that profit genuinely has to be wages.

The test that actually matters

If you hired someone else to do your job, what would you have to pay them? That figure is the starting point for your reasonable salary, and the entire decision turns on it.

Getting to it means splitting your own week honestly:

• Hours on admin - bookkeeping, scheduling, chasing invoices, keeping the lights on.
• Hours on sales and marketing - the work that brings the next client through the door.
• Hours on the work you actually sell: the billable hours, the client work, the professional service itself.
• Whether a manager already handles part of your job, which takes that piece out of your own figure.

Add it up and you land somewhere concrete: what I do is really a $40,000 job, or what I do is really a $250,000 job. In practice the figure also needs support behind it - your hours, your role, and what the market pays for that role. Those are close to the factors the IRS itself weighs, which include training and experience, duties and responsibilities, time and effort devoted to the business, and what comparable businesses pay for similar services (IRS, S corporation compensation).

Two worked examples

Run properly, the screening calculation is 15.3% of (92.35% of your profit, minus your reasonable salary). The 92.35% is not a detail we invented: self-employment tax applies to 92.35% of net profit, not all of it (IRS Schedule SE, line 4a).

Take a profit of $180,000 against a reasonable salary of $100,000. Without the election, self-employment tax applies to $166,230, which at 15.3% is about $25,400. With it, payroll taxes on the $100,000 wage come to about $15,300 and the remaining $80,000 leaves as a distribution. The difference is roughly $10,100.

Now take a profit of $90,000 against a reasonable salary of $20,000 - an owner whose own role in the business is genuinely small. Without the election, tax applies to $83,115, or about $12,700. With it, payroll on $20,000 is about $3,060. The difference is roughly $9,700.

The rough rule is that if the number comes out at $10,000 or more, an S-corp is worth taking seriously, and if it is much smaller the extra complexity may not earn its keep. Notice what that does to the second example: at about $9,700 it lands just under the bar rather than over it. A cruder 15% shortcut would have put it at $10,500 and sent that owner to a payroll company for nothing. That is the argument for running the real numbers instead of the rule of thumb.

Three things the screening number still leaves out

Even the corrected figure is a screen rather than an answer, because three real costs sit outside it.

• The Social Security ceiling. The 12.4% half only applies to earnings up to $184,500 in 2026 (IRS Publication 926). Above that only the 2.9% Medicare half continues, so profit above the ceiling saves far less per dollar than the flat calculation suggests.
• California's own bill. An S corporation pays a 1.5% California franchise tax on its net income, with an $800 minimum due every year whether the company is profitable, unprofitable, or dormant (FTB, S corporations). In the first example that is roughly $1,200 straight off the saving.
• The QBI trade. Reasonable compensation from an S corporation is excluded from qualified business income (IRS, QBI deduction), so every dollar moved from profit into salary is a dollar that no longer counts toward the Section 199A deduction.

None of that makes an S-corp a bad idea. It makes $10,000 a screening bar rather than a finding, and it is the reason two businesses with identical profit can get opposite answers.

Is this actually your business?

One question comes before all the arithmetic. If you are running a single project, or working for yourself between jobs, an S-corp is not the thing to be thinking about. Keep it simple and focus on the work. The whole calculation above is for owners who are genuinely running and trying to grow a business.

And if you do elect, do not run the payroll yourself. Payroll penalties and timing rules are strict, and they are unpleasant to unwind. Hire a payroll company rather than creating a compliance problem in the course of saving tax.

The election is the start, not the saving

The self-employment tax number is only part of why this decision matters. Setting up the entity and establishing a defensible salary often opens doors to planning that is worth considerably more later - retirement plan design being the obvious one. We have seen an S-corp save only about $5,000 in self-employment tax and still be the right call, because of what it made possible afterwards.

That cuts both ways. It is also why a $12,000 screening number sometimes still ends in a recommendation not to elect. The election is a structural decision, and structural decisions are judged on where they lead, not on one year's payroll tax.

The three questions to work through

• Is this your real business going forward, or a project you are passing through?
• If you hired someone to do your job, what would you pay them - and can you document how you got to that figure?
• Take 92.35% of your profit, subtract that salary, multiply by 15.3%. If the answer clears $10,000, an S-corp is worth a serious conversation.

Working through it with a California CPA

The arithmetic takes ten minutes. What takes longer is the documentation behind your salary figure and the question of what the election opens up next, and those are the two parts that decide whether the structure holds up. We do this work for business owners across the South Bay - tax planning in Torrance and tax planning in Palos Verdes - and for owners elsewhere in California, since every meeting runs virtually.

If you have been told that $100,000 in profit is your signal to elect, the better move is to work out what your own job is worth first. That is the number the decision actually rests on. Our tax planning page covers how the rest of the year is structured around decisions like this one.