What is the U.S. corporate tax rate for 2026?
A U.S. C corporation pays a flat 21% federal corporate income tax under Internal Revenue Code §11(b), plus a state corporate income tax that ranges from 0% (Wyoming, Nevada, South Dakota) up to about 11.5% (New Jersey, at the top surtax bracket) depending on where the corporation is doing business. This guide walks Korean-owned U.S. corporations through both layers, plus the extra federal rules that apply to foreign shareholders.
If you run a Korean parent company opening a Delaware C corporation, or you are a Korean-American founder about to check the “corporation” box on your California registration, the first question is almost always the same: what is the us corporate tax rate my company will really pay? The answer has two layers — federal and state — and both have quietly changed shape since 2017. This post gives you the short answer, the primary-source citations behind it, and the traps that hit Korean-owned U.S. corporations more often than domestic ones.
We write this for the owner, not the tax preparer. The rate numbers are exact, but we skip the return-preparation mechanics and focus on the decisions you are making right now: where to incorporate, which entity type to choose, and how to model the total tax bill before you sign a lease or a capital call.
What is the U.S. corporate tax rate at the federal level in 2026? 🇺🇸
A flat 21% of taxable income. The rate is written into the statute at Internal Revenue Code §11(b), and it applies to essentially every C corporation regardless of size, industry, or state of incorporation.
Before the Tax Cuts and Jobs Act of 2017, the federal corporate tax was a graduated bracket system that topped out at 35%. TCJA replaced the brackets with the current single 21% rate for tax years beginning after December 31, 2017, and — unlike the individual provisions of the same bill — this change did not sunset. The 21% figure is codified, not a temporary bonus. You can read the statute directly at 26 U.S.C. §11, and the IRS applies it through Form 1120 as described in the Form 1120 instructions and in Publication 542, Corporations.
Two federal add-ons matter if your U.S. subsidiary is going to be large:
- Corporate Alternative Minimum Tax (CAMT). A 15% minimum tax on the adjusted financial-statement income of very large corporations (generally, average annual AFSI over $1 billion under the applicable financial statement group test). Most Korean-owned U.S. subsidiaries never touch this threshold, but the parent’s global consolidated numbers can pull an otherwise small U.S. subsidiary into it. Details are on the IRS CAMT page.
- Base Erosion and Anti-Abuse Tax (BEAT). A separate minimum tax at §59A aimed at large multinationals that pay significant deductible amounts to foreign related parties. It kicks in only when three-year average gross receipts cross $500 million, so early-stage Korean-U.S. structures rarely see it — but transfer-pricing service fees to a Korean parent are exactly the type of payment that will be measured if you scale up.
In our practice with Korean parent companies, the most common misread of the 21% number is treating it as the total corporate tax. It is only the federal layer, and it is measured on federal taxable income — which is not the same as U.S. GAAP or K-IFRS pre-tax income. The gap between book income and taxable income (M-1/M-3 adjustments) is where surprise tax bills come from, especially when the Korean parent’s accounting policies for R&D or intercompany interest do not line up with U.S. rules under §174 and §163(j).
How much does the state add on top of the 21% federal rate? 🗺️
Between 0% and roughly 11.5%. Four states impose no corporate income tax at all, most impose a single flat rate between 4% and 8%, and a handful sit at or near 9%–11.5% at the top brackets or surtax layers.
Where your company is doing business matters far more than where you incorporated. A Delaware corporation whose only office and employees are in Los Angeles owes California corporate franchise tax on income allocated to California, regardless of the Delaware certificate. California publishes the rate and the mechanics at the FTB Corporations page: the general C-corporation rate is 8.84%, and the minimum franchise tax is $800 per year for most active corporations (see the FTB minimum franchise tax page).
Some popular states for Korean-owned companies, at a glance:
| State | C-Corp income tax | Other business-level tax |
|---|---|---|
| California | 8.84% (min. $800 franchise tax) | — |
| Delaware | 8.7% (only on Delaware-source income) | Annual Delaware franchise tax (formula-based) |
| New York | 6.5% base; 7.25% surtax bracket for large corps | NYC general corporation tax if in NYC |
| New Jersey | Up to 11.5% for large corps (CIT surtax bracket) | — |
| Texas | 0% corporate income tax | Texas franchise tax (margin tax) on gross margin |
| Washington | 0% corporate income tax | Business & Occupation (B&O) tax on gross receipts |
| Wyoming / Nevada / South Dakota | 0% corporate income tax | Nevada: commerce tax on gross revenue > $4M |
“No state income tax” does not mean “no state-level tax.” Texas replaces the corporate income tax with the franchise (margin) tax on gross margin; Washington charges a Business & Occupation tax measured on gross receipts, with no deduction for cost of goods sold in most categories; Delaware’s own franchise tax is calculated on authorized shares or assumed par value capital, and can quietly climb into five figures for startups that authorize 10,000,000 shares at $0.0001 par without also filing the assumed par value method. Model these before you assume “Delaware = free.”
Does the 21% us corporate tax rate apply to my LLC or S-corp too? 🤔
No. The 21% rate applies only to C corporations. Most single-member LLCs are disregarded entities, multi-member LLCs default to partnership taxation, and S corporations are pass-through — in all three cases, the entity pays no federal income tax and profits are taxed to the owners on their individual returns.
The IRS entity classification rules under Treas. Reg. §301.7701 give an LLC a choice: default treatment, or an affirmative election to be taxed as a C corporation (Form 8832) or an S corporation (Form 2553). The Instructions to Form 8832 lay out who can elect and when. For Korean founders, two additional rules matter:
- S corporation eligibility. An S corporation cannot have a non-resident alien shareholder. If the Korean parent company or a Korea-resident individual owns any of the shares, the S election is invalid the moment they become a shareholder. Only U.S. citizens, U.S. residents (green-card or substantial-presence), certain trusts, and estates qualify — see the S-corp eligibility rules in the Form 2553 instructions.
- Foreign-owned disregarded LLCs still file. A single-member LLC owned by a foreign person is disregarded for income tax, but the IRS requires Form 5472 with a pro forma Form 1120 reporting related-party transactions. Skipping it triggers a $25,000 penalty per year per entity. Details are in the Form 5472 instructions.
What extra federal taxes hit a Korean-owned U.S. corporation? 🌏
Three: the 30% branch profits tax (often reduced by the U.S.–Korea tax treaty), the 30% withholding on dividends paid to the Korean parent (typically 10% or 15% under the treaty), and Form 5472 reporting on related-party transactions.
The 21% rate is the same whether the shareholder is domestic or foreign. What differs is what happens to the after-tax profit when it moves back to Korea. If the U.S. subsidiary is a corporation and pays a dividend to the Korean parent, the U.S. requires 30% withholding under IRC §1442 unless a treaty rate applies. The U.S.–Korea income tax treaty (in force since 1979) reduces the dividend withholding rate — typically 10% for parent-subsidiary holdings that meet the 10% voting-stock threshold, and 15% otherwise. The IRS explains withholding on foreign payments in Publication 515, and the Form W-8BEN-E instructions from the IRS govern how the Korean parent claims the treaty rate.
If the Korean parent operates through a U.S. branch instead of incorporating a U.S. subsidiary, the branch profits tax under §884 imposes a second 30% (or treaty-reduced) tax on the dividend-equivalent amount — economically similar to withholding on a distributed dividend, but assessed at the branch level. This is the fork in the road that pushes most Korean groups toward a subsidiary rather than a branch: the treaty rate on dividends usually beats the branch-profits rate, and a subsidiary gives cleaner separation of U.S. and Korean liability.
How do I estimate the combined federal-plus-state effective rate? 🧮
For a C corporation, state income tax is deductible on the federal return (the $10,000 SALT cap does not apply to entities). The combined effective rate is roughly 21% + State% × (1 − 21%). California’s 8.84% therefore adds about 6.98% on top, for a combined ~27.98%.
Worked example. Suppose a Korean-parented Delaware C corporation, doing business only in California, has $500,000 of federal taxable income (after all M-1 adjustments). California starts from a similar base, applies its 8.84% rate for $44,200 of state tax, and that $44,200 is deductible on the federal return. Federal taxable income becomes $455,800; federal tax at 21% is $95,718. Total: $139,918, or about 27.98% of pre-state income. That is the number a Korean parent should model at board time — not the 21% headline, and not the 8.84% headline, but the combined ~28% for California operations.
A Texas-only C corporation with the same $500,000 pays 21% federally ($105,000) plus Texas franchise (margin) tax, which is measured on modified gross margin rather than net income and often lands in the 0.375%–0.75% range — a very different number. A New Jersey manufacturer with taxable income over the state’s surtax threshold can see combined federal-plus-state effective rates approach ~30%.
Summary — What Korean-owned U.S. corporations should remember
- Federal us corporate tax rate is a flat 21% under IRC §11(b), and this rate is permanent, not a TCJA sunset item.
- State corporate income tax adds 0% to about 11.5%, but “no income tax” states like Texas and Washington still charge margin tax or B&O tax.
- C-corp state income tax is deductible on the federal return, so the combined effective rate is close to Fed% + State% × (1 − Fed%).
- LLC and S-corp are not taxed at 21% — they are pass-through, and S-corps cannot have any Korea-resident shareholder.
- Dividends to a Korean parent are subject to 30% withholding under §1442, typically reduced to 10% or 15% under the U.S.–Korea treaty, on top of the corporate-level 21%.
Frequently asked questions ❓
Q1. Is the 21% federal corporate tax rate temporary or permanent?
Permanent under current law. TCJA’s individual provisions carried sunset dates, but the corporate rate change to 21% at IRC §11(b) has no sunset — it stays in effect until Congress amends the statute.
Q2. Do foreign owners pay a higher us corporate tax rate on their U.S. corporation’s profits?
The corporation itself pays the same 21%. Foreign ownership triggers additional federal rules — dividend withholding under §1441/§1442, Form 5472 on related-party transactions, potential branch profits tax under §884 if a branch is used, and BEAT at §59A once gross receipts cross $500M — but the underlying corporate rate is unchanged.
Q3. What is the corporate alternative minimum tax and does it apply to my company?
CAMT is a 15% minimum tax on adjusted financial-statement income of very large corporations, generally those with an average annual AFSI over $1 billion measured on a group basis. Small and mid-sized companies do not owe it, but a small U.S. subsidiary of a very large Korean parent can be pulled into the group calculation — check the IRS CAMT guidance.
Q4. Is state corporate income tax deductible on the federal Form 1120?
Yes. The $10,000 SALT cap in §164(b)(6) applies to individuals, not to C corporations. A C corporation deducts state income tax accrued during the year on line 17 of Form 1120 — see the Form 1120 instructions.
Q5. What if my U.S. entity is an LLC — how do I know the actual tax rate?
A single-member LLC is disregarded, so profits flow through to the owner (individual rates, or the foreign owner’s home-country return). A multi-member LLC defaults to partnership taxation on Form 1065 — again pass-through. Only if the LLC affirmatively elects C-corp treatment on Form 8832 does the 21% federal rate apply.
Q6. If I incorporate in Delaware but operate in California, whose corporate tax do I pay?
Both, in different ways. Delaware taxes only Delaware-source income (usually zero for an out-of-state operation), but Delaware’s separate franchise tax applies to any Delaware-incorporated entity. California taxes income apportioned to California under the FTB rules, plus the $800 minimum franchise tax. The Delaware certificate does not shield you from California corporate tax when the business is actually run in California.
Written by SW Accounting & Consulting Corp (Los Angeles). This post is educational and not a substitute for advice on your specific facts — reach out if you’d like us to model the combined federal-plus-state rate for your U.S. subsidiary.
