Converting a C-Corp to S-Corp: Built-In Gains Tax, Timing, and the 5-Year Recognition Period
Converting a C-Corp to an S-Corp is one of the most requested tax planning moves for small business owners who started as C-Corps (or whose LLC defaulted to C-Corp treatment) and want to access the pass-through tax benefits: QBI deduction, avoidance of double taxation, and SE tax savings through salary/distribution splitting. The conversion itself is a tax election (Form 2553), not a restructuring, and it doesn’t trigger immediate tax. However, the built-in gains (BIG) tax under IRC 1374 creates a 5-year lookback period that limits the tax benefit on appreciated assets.
C-Corp to S-Corp conversion essentials:
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The election is straightforward. File Form 2553 (Election by a Small Business Corporation) with all shareholder consents. The deadline is March 15 for a calendar-year conversion effective January 1.
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S-Corp eligibility requirements: 100 or fewer shareholders, all US citizens or residents, only one class of stock, no corporate or partnership shareholders.
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The built-in gains tax (IRC 1374). Any asset that was appreciated at the time of conversion and is sold within 5 years of the conversion date triggers a corporate-level tax at the highest corporate rate (21%) on the built-in gain. This prevents a business from converting to S-Corp and immediately selling appreciated assets at pass-through rates.
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AAA and E&P tracking. A former C-Corp that converts retains its accumulated earnings and profits (E&P). Distributions first come from the accumulated adjustments account (AAA, post-S-Corp earnings) tax-free (return of basis), then from E&P (taxed as dividends). The E&P layer must be tracked until it’s fully distributed or eliminated.
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LIFO recapture (IRC 1363(d)). If the C-Corp used LIFO inventory, the excess of FIFO value over LIFO value is included in the final C-Corp return as income. Tax is paid over 4 years.
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Passive income limitation. An S-Corp with C-Corp E&P that receives more than 25% of gross receipts as passive investment income for 3 consecutive years risks losing the S-Corp election. Rental income, interest, dividends, and royalties count. Distributing the E&P eliminates this risk.
When does the built-in gains tax matter?
The best time to convert is when the business has minimal appreciated assets and the owner is ready to commit to the S-Corp structure for at least 5 years. Converting early in the business lifecycle (before assets appreciate significantly) minimizes BIG tax exposure.
After a C-Corp converts, can the owner skip salary?
No. Once the S election takes effect, an owner who works in the business is still a corporate officer, and officers are employees for payroll tax purposes. The IRS says an S-Corp must pay a shareholder-employee reasonable compensation before it makes non-wage distributions, and it can reclassify distributions as wages if the salary is too low.
That matters in the first years after a conversion, when it’s tempting to move profit out as distributions (the article covers how AAA and E&P decide the income tax side of those). The Code and regulations give no dollar figure or ratio. Courts look at the facts, including training and experience, duties, time spent, what comparable businesses pay for similar services, and the company’s dividend history.
The main court example is David E. Watson, P.C. v. United States (8th Cir. 2012). An accountant paid himself $24,000 a year while taking $203,651 and $175,470 in distributions for 2002 and 2003. The court set his reasonable pay at $91,044 a year, and the judgment included unpaid employment taxes, penalties and interest.
Can I change my entity structure after I’ve already started operating?
Yes, but timing and method matter. Converting from a sole proprietorship to an LLC is straightforward and can happen at any time by filing articles of organization with your state. Electing S-Corp status requires filing Form 2553 within 2 months and 15 days of the start of the tax year you want it to take effect. Late elections are available under Revenue Procedure 2013-30 if you can demonstrate reasonable cause. Converting from an S-Corp to a C-Corp or vice versa has additional tax consequences, including potential built-in gains tax, so the timing should be planned with a tax advisor.
Related guides:
- Cannabis Entity Structure: LLC, S-Corp, or C-Corp Under 280E?
- S-Corp Election Timing: Form 2553 Deadlines, Late Elections, and When to Wait
- Built-In Gains Tax for S-Corps: How IRC 1374 Applies When Converting from C-Corp
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Yarik Yarosh, CPA. "Converting a C-Corp to S-Corp: Built-In Gains Tax, Timing, and the 5-Year Recognition Period." Blue Cloud CPA, September 5, 2026, updated September 23, 2026. https://bluecloudcpa.com/guides/small-business-converting-c-corp-to-s-corp
This guide is general information, not tax advice for your specific situation. Which points apply, and how, depends on your facts.