How to Build a Tax Plan for an S Corp Owner

Which S corp owner is worth a tax plan?

First, let’s give a quick preface. Not every S corp client needs a full plan. The owner worth your time usually looks like this:

• Structure: a single-owner (or married-couple) S corp where the owner works in the business full time.
• Profit: roughly $150,000 to $600,000 of profit before owner pay. That's our working range; the IRS sets no threshold. Below it, the S corp often saves little after payroll and filing costs. Above it, the §199A wage and specified-service limits start to apply, and the plan gets more involved.
• Return signals:
  • Form 1120-S: officer compensation on line 7 that looks small next to ordinary business income, a blank line 17 (pension and profit-sharing plans), and a blank line 18 (employee benefit programs).
  • Form 1040: nothing on Schedule 1 line 16 (retirement plans), line 17 (self-employed health insurance), or line 13 (HSA deduction).

That last set of signals is the fastest screen you have. Three blank lines on a return with $300,000 of flow-through income is a client who's paying more than they should.

The example S Corp client paying too much

Dana is 52 and owns a digital marketing agency in Texas, which keeps this example federal-only. Here's her setup going into 2026:

If nothing changes, Dana's 2026 federal income tax plus total FICA on her salary comes to $61,607. That number looks fine until we look closer:

1. A $60,000 salary against $380,000 of profit that she mostly generates herself. That's an exposure the IRS can reclassify.
2. A $24,000 health premium producing zero deduction.
3. About $16,500 of business costs producing zero deduction.
4. No retirement contributions at 52.
5. An HSA with a qualifying plan and nothing in it.

Download the Accountant’s 12-Month Tax Planning Calendar

S corp tax plan: set reasonable compensation

The tax code never gives you a salary number. It gives you a rule: an S corp has to pay a shareholder-employee reasonable compensation before it pays out distributions. If the salary is too low, the IRS can reclassify distributions as wages.

The IRS lists the factors it looks at on its S corporation compensation and medical insurance issues page:

• training and experience
• duties
• time devoted to the business
• dividend history
• pay to non-shareholder employees
• bonus timing
• what comparable businesses pay
• compensation agreements
• the use of a formula

The case that shows what happens when the salary is too low is David E. Watson, P.C. v. United States. Watson, an accountant, ran his practice through an S corp and paid himself $24,000 a year in 2002 and 2003. In those same years, he took profit distributions of $203,651 and $175,470. The government's expert valued his work at $91,044 a year. The district court agreed, and the Eighth Circuit upheld it.

You don't have to build this number by hand. Use a service like RCReports to produce a reasonable compensation report for each S corp client:

• The client answers a guided interview about duties, hours, and qualifications.
• The report breaks the owner's work into separate roles and prices each one using wage data for their location.
• It backs the final number with IRS criteria and court cases.

Keep the report in the client file and rerun it every year. If the IRS questions the salary, you hand over a documented analysis.

You'll hear about the "60/40 rule" (60% salary, 40% distributions). It isn't in the tax code or the regulations, and it won't hold up if the IRS audits the return.

Building an S Corp owner’s number

1. Time allocation. Dana's calendar shows about 65% of her hours on client strategy and directing contractors, and 35% on sales, finance, and admin.
2. Benchmark. The Bureau of Labor Statistics reported a national median of $166,790 for marketing managers in May 2025. That's a full-time, all-industry national figure that includes large corporate employers, so the plan uses it as a ceiling check.
3. Reasonable compensation report. The accountant runs Dana through something akin to RCReports. For this hypothetical, assume the report prices her client strategy, sales, and admin roles for her metro area and lands at $140,000.

The plan sets Dana's salary at $140,000, backed by RCReports and a corporate resolution setting the salary.

The salary versus distribution split in an S corp tax plan

Every dollar of W-2 pay does three things at once:

• It costs 15.3% in combined FICA. Social Security applies up to the $184,500 wage base for 2026, and Medicare has no cap.
• It cuts the QBI deduction by at least 20 cents.
• It adds 25 cents of employer 401(k) capacity.

The table below runs Dana's full plan from Steps 3 through 5 at six salary levels. Every row includes the same health, HSA, accountable plan, and solo 401(k) treatment.

Every extra $20,000 of salary adds about $2,791 to Dana's federal tax bill. It also lets her put another $5,000 into her 401(k).

On paper, the $60,000 salary looks like the winner, at $11,163 cheaper than paying her $140,000. It's also the number most likely to get the IRS's attention. Say the IRS decided $80,000 of her distributions should have been salary. She'd owe about $12,240 a year in extra payroll tax, plus penalties and interest, for every year the IRS can still review.

At $140,000, Dana still takes $153,748 out of the business as distributions, with no payroll tax on that money. And it's a salary she can back up with her time log and the market data.

2026 timing matters. Dana has been paid at a $60,000 pace this year, about $5,000 a month, so she's received about $45,000 through September. To reach $140,000 for 2026, she needs about $95,000 more in salary from October through December, roughly $31,700 a month. The IRS looks at the full-year total, so a fourth-quarter catch-up still counts.

The bigger paychecks help in a second way. Quarterly estimated payments count on the day they're paid, but the IRS treats tax withheld from wages as if it had been paid evenly across the whole year, even when most of it comes out in December (§6654(g)). If Dana shorted her estimates earlier in 2026, the extra withholding from her fourth-quarter paychecks can cover the gap and reduce or erase the underpayment penalty.

Accountable plan reimbursements for the S corp owner

Inside the S Corp, Dana is an employee of her own corporation, and her unreimbursed employee business expenses simply aren't deductible. The One Big Beautiful Bill Act from 2025 made the loss of miscellaneous itemized deductions permanent. An accountable plan under Treas. Reg. §1.62-2 is the route here: the S corp reimburses Dana, deducts the reimbursement, and the payment stays off her W-2.

The plan should meet 3 tests: a business connection, substantiation within a reasonable period, and return of any excess. Under the fixed-date safe harbor, that means there has to be substantiating within 60 days and returning excess within 120 days.

Dana's 2026 reimbursements:

Two 2026 details to get right:

• The mileage rate changed mid-year. The IRS set the 2026 business rate at 72.5 cents in Notice 2026-10. It then raised the rate to 76 cents for miles driven July 1 through December 31 in Announcement 2026-11. Dana's log has to split the year, and so does the reimbursement.
• Home office rules are stricter for employees. Under §280A(c)(1), an employee's home office has to be for the employer's convenience, on top of the usual regular and exclusive use tests. Dana's file should show the agency has no other office where she does this work. Her reimbursement leaves out depreciation. That keeps the calculation simple and avoids a basis question when she sells the house.

For future equipment, the S corp can buy it directly. For 2026, §179 allows up to $2,560,000 of expensing, and 100% bonus depreciation is back for property acquired after January 19, 2025.

Retirement plan selection for an S corp owner

For an S corp owner, retirement contributions run off W-2 wages only. Distributions don't count.

Here's how the three options compare for Dana at a $140,000 salary:

Solo 401(k) wins for Dana. In the full plan, it saves $7,459 more in federal tax than a SEP and shelters $32,500 more. The deferral piece is what the SEP can't match. Dana's 2025 FICA wages were under $150,000, so under the SECURE 2.0 Roth catch-up rule her 2026 catch-up can go in pre-tax.

The deadlines for the solo 401(k):

• The plan document must be signed, and the deferral election made, before the wages it covers are paid.
• The deferrals have to run through payroll.
• The employer contribution can wait until the 1120-S due date, including extensions.
• Once plan assets pass $250,000, Dana files Form 5500-EZ.

One condition can break this strategy: the contractors have to be real contractors. If any of the six should be W-2 employees, the solo 401(k) isn't available and you're designing a plan that covers staff.

SEP wins in three cases:

• The owner comes to you after year-end. You can still set it up and fund it by the extended due date.
• The salary is high enough that 25% reaches $72,000 (at $288,000 of W-2 pay) and the owner has no catch-up to add.
• Simplicity outweighs the dollars.

Defined benefit or cash balance wins for owners 50 and older with steady profits who want to shelter well past $72,000 a year and can commit to annual funding. Pairing one with a 401(k) brings in the §404(a)(7) combined deduction limit, which usually caps the profit-sharing contribution at 6% of pay. Elective deferrals don't count against it. Get the actuary's illustration before you promise a number.

Dana doesn't get one in 2026. The §415(b) limit caps her annual benefit at 100% of her highest three-year average compensation, and her $60,000 salary years drag that average down. A cash balance plan belongs on the table for 2027 or 2028, once the $140,000 salary is on record and her profit holds.

Health insurance and HSA for a more-than-2% S corp shareholder

If you own more than 2% of an S corp, the IRS treats you like a partner when it comes to fringe benefits. The S corp can't give Dana tax-free health coverage the way it could for a regular employee. And since Dana pays her $24,000 premium out of her own pocket, she gets no deduction for it at all.

Health insurance. The fix comes from Notice 2008-1, and it takes two steps:

1. The S corp pays the premium, or reimburses Dana for it, and adds it to Box 1 of her W-2. It stays out of Boxes 3 and 5, so no payroll tax applies.
2. Dana deducts the premium on her personal return as self-employed health insurance, using Form 7206.

Dana loses the deduction for any month she or her spouse could get subsidized coverage through an employer. Neither can, so she gets the full deduction.

There's one catch. The Form 8995 instructions say the self-employed health insurance deduction reduces QBI. The premium already cut Dana's S corp profit when the business paid it, so it ends up reducing QBI twice. For Dana that second cut costs $1,152 in 2026. Build it into the plan so the client isn't surprised by it later.

HSA. A more-than-2% shareholder can't make pre-tax HSA contributions through a cafeteria plan. That leaves two routes:

• The S corp contributes. The contribution goes in Box 1 wages and is deducted on Form 8889. It's free of FICA under Notice 2005-8 when made under a plan for employees.
• Dana contributes personally and deducts it on Form 8889.

For Dana, personal funding is better. Her salary is already set by the reasonable compensation analysis, so an S corp contribution doesn't replace any wages. It just shrinks her K-1 and her QBI deduction. Funding the $8,750 family maximum personally, out of distributions, saves her $385 more than routing it through the S corp. The FICA angle only pays off when the HSA contribution would otherwise have been salary.

The 2026 family limit is 8,750(4,400 self-only), plus $1,000 at 55. Dana has until April 15, 2027 to fund it.

Stacking the S corp tax plan: projected savings

Here's the full 2026 federal picture, built one strategy at a time.

Here's how to read the table:

• Against a defensible setup (B), the plan saves $22,911 in 2026 federal tax.
• Against what she's doing today (A), her bill drops $8,006, even after absorbing $14,905 of extra tax from fixing her salary.
• $67,500 moves into her 401(k) instead of her checking account.
• The salary exposure closes. That's roughly $12,240 a year of FICA that isn't hanging over her anymore.

Show the client all four. The $8,006 on its own makes the plan look small, and the $22,911 on its own overstates what changes in her bank account.

A client in a state with an income tax needs the state layer modeled on top, including any pass-through entity tax election.

Documentation that holds up the S corp tax plan

For each piece of Dana's plan:

• Reasonable compensation: The reasonable compensation report, rerun annually and corporate resolution setting the salary. Salary paid through regular payroll, not a single December entry.

• Health insurance:
  • Premiums paid by the S corp, or reimbursed with proof.
  • The amount in W-2 Box 1 before the W-2 is filed.
  • A note confirming neither spouse was eligible for a subsidized employer plan.
• HSA: proof the plan is HSA-qualified, contribution records, and Form 8889.
• Accountable plan:
  • A written plan adopted by corporate resolution.
  • An expense report for each reimbursement.
  • A contemporaneous mileage log with date, miles, destination, and business purpose, as §274(d) requires.
  • Home office measurements, photos, and a note on why the space is for the corporation's convenience.
  • Receipts for equipment and utilities.
• Solo 401(k):
  • The signed adoption agreement, dated before year-end.
  • Dana's written deferral election.
  • Payroll records showing the deferrals, and the employer deposit date.
  • Form 5500-EZ once assets pass $250,000.
  • The contractor agreements and 1099s, kept in the same file. They're the reason the plan is solo.

Turning the S corp tax plan into a client-ready plan and a fee

Dana doesn't need your spreadsheet. She needs a quick one-page summary of what she can save and what the investment would be.

Price it with the ROI Method of Value Pricing. The client should see at least a 200% return on what they pay you. Set a fixed fee up front that takes into account the CURB framework:

• Complexity
• Urgency
• Risk
• Benefits and burden

A fixed annual fee of $7,500 can give Dana a projected 205% return on the first-year savings alone. Price against the $22,911, and explain to Dana why that's the right comparison: her real alternative is the $60,000 salary plus the exposure.

Software for building an S corp tax plan

When you're comparing options, check whether the software can:

• Model multiple scenarios for a client
• Start from the prior-year 1040 instead of manual data entry
• Project state tax alongside federal in the same workflow
• Create a detailed tax plan

TaxPlanIQ's Projections module covers most of that list:

• You can build up to five scenarios per client and compare them side by side, starting from an uploaded 1040.
• For clients who haven't elected S status yet, Entity Engine models the election side by side with the current setup
• State tax is projected in the same workflow as federal

Beyond Projections, TaxPlanIQ includes a library of 130+ advanced tax planning strategies. The ROI Method of Value Pricing is the pricing framework TaxPlanIQ teaches firms for engagements like Dana's.

TaxPlanIQ Projections include entity comparisons and scenario modeling.