S-Corp Election: Writing the Entity Selection Memo

Every fall, a few owners ask the same question: should my business be an S corp next year? It's a fair question, and it deserves a written answer. That answer is an entity selection memo. It records the client's facts, the salary assumption, the comparison, the recommendation and the Reviewer's sign-off, before anyone files Form 2553. An S corp election for 2027 can be filed any time in 2026, so the memo belongs on the calendar now, not in March.

This guide walks through what the memo holds, how to run the break-even analysis with reasonable compensation, payroll cost and state tax in it, and the Form 2553 timing rules your file should cite.

LLC vs S corp is a tax question, not a legal one

Clients say "LLC or S corp" as if they were two kinds of company. They aren't. An LLC is formed under state law. S corporation status is a federal tax election. A single-member LLC that never elects is taxed as a sole proprietorship, and its owner pays self-employment tax on the business's net earnings.

An eligible LLC doesn't have to convert to make the election. Under the Form 2553 instructions, an eligible entity that timely files Form 2553 is treated as having elected to be classified as a corporation, so a separate Form 8832 isn't required. The entity still has to pass the eligibility tests in IRC §1361(b): a domestic entity, only allowed shareholders, within the shareholder limit, and one class of stock. The memo records each test and the fact that satisfies it.

That framing keeps entity selection honest. The legal wrapper usually stays the same. What changes is how the owner gets paid, what the firm files, and what it costs to run.

The memo, section by section (copy-ready)

Copy this table into your firm's entity selection template. Each row is one section of the memo, with the evidence it rests on and who signs it.

The salary row carries the most weight, and it's the one clients push on. How the salary is set is its own analysis; the guide to determining reasonable compensation covers it. The memo's job is to state the figure, cite where it came from and carry it into the worksheet unchanged.

The break-even analysis

The savings from an S election come from one place: Social Security and Medicare stop applying to the part of the profit paid out as distributions instead of salary. Everything else in the worksheet either shrinks that number or decides whether it's real.

The inputs

• Net profit from the books, with the current-year projection shown next to the prior year.
• The salary assumption from the salary section, unchanged.
• Payroll taxes on the salary: Social Security on wages up to $184,500, which works out to a maximum of $11,439 on each side, plus Medicare at 1.45% on each side with no wage cap (SSA announcement, 2025-10-24; IRC §3101(b); as of 2026-09-23). Additional employee Medicare applies above $200,000 of wages.
• Payroll cost: the payroll service, quarterly filings and year-end W-2. The owner becomes an employee, and the payroll requirements for S-corp owners all apply.
• The added return: the corporate return and the K-1, at your firm's own fee.
• State tax: some states tax S corporations at the entity level or charge an annual fee, and not every state treats the entity the way the federal election does. The memo cites the client's state rule with a date.

An illustrative example

Illustrative example: a single-member LLC projects $150,000 of net profit. The salary assumption from the owner's Study is $80,000. Payroll tax on each side is the 6.2% Social Security rate implied by the $11,439 maximum on $184,500 of wages, plus 1.45% Medicare, so 7.65% per side and 15.3% combined. The cost figures below are placeholders for your firm's own quotes and the client's state rule. They aren't any state's rate or any vendor's price.

Actual results vary based on income, industry, and state.

The break-even point falls out of the same arithmetic. With $3,200 of added cost, the election pays only when profit above salary exceeds about $20,915 ($3,200 divided by 15.3%). Below that, the costs eat the savings.

These are gross figures. The memo's final worksheet adjusts them on the client's actual return: the self-employment tax computation on net earnings, the deduction for half of self-employment tax, unemployment taxes on the salary, the employer's deduction for its share of payroll tax, and the qualified business income deduction, which moves when the split between salary and profit moves. None of those adjustments is stated here as a number. Each belongs in the worksheet with its source.

Look at the two S-election columns again. A $30,000 change in the salary assumption cut the net difference from $7,510 to $2,920. That's why the salary row gets a Reviewer's signature and not just a Preparer's estimate. Salary also sets the ceiling on employer retirement contributions, since profit-sharing and SEP deductions run up to 25% of W-2 compensation and distributions don't count (IRC §404(a)(3); IRC §404(h)). The retirement plan comparison sits on that same salary figure.

Timing: Form 2553 and late election relief

Form 2553 must be filed no more than 2 months and 15 days after the beginning of the tax year the election is to take effect, or at any time during the preceding tax year (Form 2553 instructions, as of 2026-09-23). For a calendar-year business electing for 2027, that means any time in 2026 or in the first 2 months and 15 days of 2027. Filing in the fall lets payroll start with the first paycheck of the year instead of catching up later.

Every shareholder consents on the form. The memo's timing section lists who signs and when the signed form went out.

If the deadline passes, Rev. Proc. 2013-30 generally allows late election relief within 3 years and 75 days of the intended effective date, when there's reasonable cause and the returns have been filed consistently with the election (irs.gov "Late election relief", updated 2026-07-20). That's a remedy, not a schedule. A memo that plans on relief has already missed its date.

What the Reviewer checks before signing

The Reviewer's check is about traceability: each section should lead back to its source in a minute or two.

• The salary matches the Study or analysis it came from, with no rounding on the way into the worksheet.
• The worksheet arithmetic recomputes, and every rate carries a source and an as-of date.
• The state line cites the client's state, not a general rule.
• The election date matches the Form 2553 window, and every shareholder consent is on file.
• The conditions say what would change the answer: a drop in profit, a new owner, a move to another state.

Once it's signed, the memo feeds the client's planning file. The S-corp tax planning memo picks up the same salary figure in its salary section the following year.

Conclusion

An entity selection memo turns "should I be an S corp?" into a file someone else can check: the facts, the salary, the arithmetic, the state rule, the date and a signature. Write it before Form 2553 goes out, and the election has a record behind it.

TracePrep ships one workflow today, the Reasonable Compensation Study, with traceable evidence and Reviewer sign-off on workpapers your firm owns. It's the salary support the memo's salary section cites. A tax-planning workflow is in development.

Get started or see how a Study is built.

Not tax advice. This article explains general rules as of 2026-09-23. Apply them to a client's facts with your firm's own professional judgment.

TracePrep is a software product from TracePrep Inc., not a CPA firm. This content is operator experience for educational purposes; it is not tax advice and has not been reviewed by a licensed CPA. Consult a qualified tax professional for guidance on your specific situation. Source citations in TracePrep workpapers support audit defense but do not guarantee IRS outcomes.