Most entity comparisons focus on self-employment tax and stock classes, but the S-Corp versus C-Corp decision turns on a different set of factors. Double taxation, the exclusion of gain on qualified small business stock, and a five-year corporate-level tax exposure period that follows a C corporation through any later S election all bear on this choice, and their consequences often do not become apparent until a client is already engaged in fundraising, an exit, or a conversion whose tax cost was not fully evaluated in advance.
Lincoln PLLC advises CPAs and business attorneys on this kind of structural tax planning, particularly for clients weighing a C-Corp against an S-Corp with an eye toward outside investment or a future sale. Our business law team works through the entity analysis with the attorney handling formation, so the client’s long-term plans, not just this year’s tax return, drive the decision.
Double Taxation Can Be Deferred but Rarely Eliminated
A C-Corp pays federal income tax at a flat 21 percent rate on its taxable income (IRC § 11(b)), and any profit distributed to shareholders as a dividend is taxed again at the individual level, at a federal rate of up to 23.8 percent on qualified dividends (IRC § 1(h)(11)) once the 3.8 percent net investment income tax applies (IRC § 1411). An S-Corp generally avoids that second layer, since its income passes through and is taxed to shareholders once (IRC § 1366), whether or not it is distributed, although an S corporation that was formerly a C corporation can owe corporate-level tax on built-in gains (IRC § 1374), as discussed below.
The second level of tax is not triggered by simply operating as a C-Corp. It is triggered when earnings leave the corporation, most commonly as a dividend, and also when shareholders sell their stock or the corporation liquidates. A business reinvesting most of its earnings, or paying owners reasonable compensation rather than dividends, can defer the second layer for years, subject to the accumulated earnings tax on earnings retained beyond the reasonable needs of the business and the risk that compensation found to be unreasonable will be recharacterized as a nondeductible dividend. That distinction matters more than the simple rate comparison most clients hear, since a C-Corp designed to retain earnings and a C-Corp designed to distribute them face different tax results.
Section 1202 Is a C-Corp-Only Advantage
Qualified small business stock, under Internal Revenue Code Section 1202, allows a noncorporate shareholder to exclude up to 100 percent of the gain on a sale of qualifying stock, provided the stock was acquired at original issuance from a domestic C-Corp that meets the gross asset and active business requirements and held long enough to meet the statutory holding period. For stock issued after July 4, 2025, the exclusion is 50 percent after three years, 75 percent after four years, and 100 percent after five years; the per-issuer cap on excluded gain is generally the greater of $15 million or 10 times the shareholder’s basis; and the issuer’s aggregate gross assets cannot exceed $75 million when the stock is issued. Stock issued on or before July 4, 2025 generally must be held for more than five years and is subject to a $10 million cap (or 10 times basis, if greater) and a $50 million gross asset limit. Stock issued by an S corporation does not qualify, and interests in an LLC taxed as a partnership or disregarded entity do not qualify, although an LLC that has elected to be taxed as a C corporation can issue qualifying equity. A business in certain service fields, including law, accounting, consulting, health, and financial services, cannot satisfy the active business requirement.
For a client anticipating outside investment or a future acquisition, this single provision can outweigh the self-employment tax considerations that usually dominate the LLC-versus-S-Corp analysis. A founder planning to raise venture capital or build toward a sale in the next several years should evaluate this exclusion before the entity choice is made, not after the cap table is set.
The Built-In Gains Tax Applies for Five Years After a C-Corp Conversion
A C-Corp that later elects S-Corp status does not leave the corporate-level tax exposure behind entirely. Under Section 1374, built-in gain that existed when the S election took effect- meaning the excess of the value of assets the corporation already held (including goodwill and receivables) over their tax basis- is taxed at the corporate level at the 21 percent rate (IRC § 1374(b)(1)) if it is recognized during the five-year recognition period (IRC § 1374(d)(7)), up to the corporation’s net unrealized built-in gain on that date (IRC § 1374(c)(2)). This recognition period begins on the first day of the first taxable year for which the corporation is an S corporation, per Section 1374 of the Internal Revenue Code, and it applies regardless of how long the business has otherwise been operating. A former C corporation that retains accumulated earnings and profits can also owe corporate-level tax on excess net passive income (IRC § 1375), and its S election terminates if passive investment income exceeds 25 percent of gross receipts for three consecutive taxable years (IRC § 1362(d)(3)).
This is the part of the analysis that is overlooked most often, because the exposure must be evaluated at conversion but produces no tax until a later sale. By the time a business is selling an appreciated asset, the conversion decision may be years in the past, and the entity’s tax history is easily overlooked. An attorney advising a client on converting an existing C-Corp to an S-Corp should identify this exposure and consider obtaining an appraisal of the corporation’s assets as of the effective date, before the election is filed.
Fringe Benefits and Ownership Rules Favor the C-Corp
C-Corps can provide certain fringe benefits, such as health insurance and group term life insurance, to owner-employees on a tax-free basis. An S-Corp shareholder who owns more than 2 percent of the company is treated like a partner for fringe benefit purposes, so the S-Corp’s payment of those benefits is generally included in the shareholder’s wages, although the shareholder may be able to deduct health insurance premiums on the individual return. C-Corps also face no restriction on the number, residency, or type of their shareholders. By contrast, an S-Corp cannot have a nonresident alien, a partnership, or a corporation as a shareholder, with the limited exception of an S corporation parent that owns 100 percent of a subsidiary and elects to treat it as a qualified subchapter S subsidiary.
These differences matter most for businesses with international ownership or a benefits-heavy compensation structure, situations where the S-Corp’s tax savings on distributions can be outweighed by what the structure cannot accommodate. Our tax law team addresses this structural analysis alongside the more commonly discussed tax rate comparison, often in coordination with the transactional business tax work that covers the entity’s ongoing planning needs.
Talk to Lincoln PLLC Before the Cap Table Is Set
Lincoln PLLC has advised on entity structuring and corporate transactions since Erik Lincoln founded the firm in 2014, bringing both a law license and a CPA license to the tax side of every transaction. Working with clients in Charlotte, Raleigh, and nationwide, our team regularly sees the same pattern: a QSBS opportunity or a built-in gains exposure that was not identified until it was too late to plan around.
If you are advising a client on a C-Corp versus S-Corp decision, or on a conversion between the two, contact our team while the structure is still in planning, before any election or formation document is filed.