Gross Income

総所得

全ての所得の総額。除外項目を差し引く前

Gross income includes wages, interest, dividends, and all other income from whatever source derived.

Adjusted Gross Income (AGI)

調整後総所得

Gross Income - Above-the-line deductions

AGI is calculated by subtracting above-the-line deductions from gross income.

Taxable Income

課税所得

AGI - Standard/Itemized Deduction - QBI Deduction

Taxable income is the amount subject to federal income tax after all deductions.

Standard Deduction

標準控除

定額の控除。項目別控除との選択制

Most taxpayers choose the standard deduction because it exceeds their itemized deductions.

Itemized Deduction

項目別控除

医療費、州税、住宅ローン利息、寄付金等

Itemized deductions include medical expenses, state taxes, mortgage interest, and charitable contributions.

Filing Status

申告資格

MFJ, MFS, HH, Single, QSS の5種類

Filing status determines the tax brackets and standard deduction amount.

Above-the-Line Deduction

AGI控除（ライン上控除）

AGI算出前に差し引ける控除。IRA拠出、学生ローン利息等

Above-the-line deductions reduce AGI and are available regardless of whether the taxpayer itemizes.

Capital Gain

キャピタルゲイン

資産売却益。短期（Ordinary）vs 長期（優遇税率）

Long-term capital gains held over one year are taxed at preferential rates of 0%, 15%, or 20%.

Ordinary Income

通常所得

累進税率が適用される所得。賃金、利息、短期CG等

Wages, salaries, and interest income are all taxed as ordinary income.

Qualified Business Income Deduction (§199A)

適格事業所得控除

パススルー事業所得の最大20%を控除

The QBI deduction allows eligible taxpayers to deduct up to 20% of qualified business income.

Tax Credit

税額控除

税額を直接減少させる。控除よりも有利

A $1,000 tax credit reduces taxes owed by $1,000, regardless of the taxpayer's marginal rate.

Marginal Tax Rate

限界税率

追加$1の所得に適用される税率

The marginal tax rate is the rate applied to the next dollar of taxable income.

Constructive Receipt

推定受領

所得を受領可能な状態になった時点で認識

Under the constructive receipt doctrine, income is recognized when it becomes available without restriction.

Exclusion from Gross Income

総所得からの除外項目

贈与、相続、市債利息、生命保険金等

Gifts, inheritances, and municipal bond interest are excluded from gross income.

SALT Deduction

州・地方税控除

州税・地方税の項目別控除。$10,000上限

The SALT deduction for state and local taxes is capped at $10,000 for individuals.

Child Tax Credit

児童税額控除

適格扶養児童1人あたりの税額控除

The child tax credit provides a per-child credit that directly reduces tax liability.

Earned Income Credit (EIC)

勤労所得税額控除

低所得勤労者向けの還付可能な税額控除

The EIC is a refundable credit that provides tax relief to low-income working individuals.

Depreciation (MACRS)

減価償却（MACRS）

税務上の減価償却方法。加速償却

MACRS is the tax depreciation system that provides accelerated cost recovery for business assets.

Section 179 Expense

§179即時費用化

適格事業用資産の取得年度に全額費用化

Section 179 allows businesses to expense the full cost of qualifying assets in the year of purchase.

Alternative Minimum Tax (AMT)

代替最低税

通常の税額と比較して高い方を支払う

AMT ensures that taxpayers with significant deductions pay at least a minimum amount of tax.

Basis Limitation

ベイシス制限

損失控除は投資のBasis（税務基準額）が上限

A partner cannot deduct losses in excess of their adjusted basis in the partnership.

At-Risk Rules

アット・リスク・ルール

損失控除はAt-risk amount（自己資金+返済義務のある借入）が上限

The at-risk rules limit loss deductions to amounts the taxpayer has economically at risk.

Passive Activity Loss (PAL) Rules

受動的活動損失ルール

Passive lossはPassive incomeのみと相殺。Active/Portfolio不可

Passive activity losses can only offset passive activity income, not wages or investment income.

Material Participation

実質的参加

年間500時間以上等の7テスト。満たせばActive

A taxpayer who works more than 500 hours in an activity is considered to materially participate.

Passive Activity

受動的活動

実質的に参加していない事業活動。不動産賃貸含む

Rental activities are generally treated as passive regardless of the taxpayer's participation.

Portfolio Income

ポートフォリオ所得

利息、配当、キャピタルゲイン。Passiveと相殺不可

Interest and dividends are portfolio income and cannot be offset by passive losses.

$25,000 Rental Exception

$25,000賃貸例外

Active参加の賃貸損失を最大$25,000控除可能

An individual who actively participates in rental activities may deduct up to $25,000 of rental losses.

Suspended Loss

繰越損失

制限で控除できなかった損失。将来年度に繰越

Suspended passive losses carry forward and may be deducted against future passive income.

Excess Business Loss Limitation

過大事業損失制限

個人の事業損失の控除上限。超過分はNOLに繰越

Excess business losses above the threshold are treated as a net operating loss carryforward.

Net Operating Loss (NOL)

純営業損失

事業損失が他の所得を超過した金額。無期限繰越

NOLs can be carried forward indefinitely and offset up to 80% of taxable income.

At-Risk Amount

アット・リスク金額

自己資金 + 返済義務のある借入金

The at-risk amount includes cash invested and amounts borrowed for which the taxpayer is personally liable.

Capital Loss Limitation

資本損失の制限

個人: Net CL は年間$3,000まで通常所得と相殺可能

Individuals can deduct up to $3,000 of net capital losses against ordinary income per year.

Loss Limitation Ordering

損失制限の適用順序

Basis → At-risk → Passive の順で適用

Loss limitations are applied in order: first basis, then at-risk, then passive activity rules.

Real Estate Professional Exception

不動産専門家の例外

年間750時間以上の不動産活動で賃貸がActiveに

A qualifying real estate professional can treat rental activities as nonpassive.

Disposition of Passive Activity

受動的活動の処分

全処分時に繰越損失を全額控除可能

Upon a fully taxable disposition, all suspended passive losses become deductible.

Annual Exclusion (Gift Tax)

年間除外額（贈与税）

受贈者1人あたりの非課税限度額

Gifts up to the annual exclusion amount per donee are not subject to gift tax.

Unified Credit

統一税額控除

贈与税・遺産税で共通の生涯非課税枠

The unified credit shelters a certain amount of lifetime gifts and estate transfers from tax.

Gross Estate

総遺産額

死亡時のFMVで評価。保険金、信託含む

The gross estate includes the fair market value of all property owned at the date of death.

Marital Deduction

配偶者控除

配偶者への移転は無制限に控除可能

The unlimited marital deduction allows tax-free transfers between U.S. citizen spouses.

Charitable Deduction (Estate)

慈善控除（遺産税）

適格慈善団体への遺贈は全額控除

Bequests to qualified charities are fully deductible from the gross estate.

Gift Splitting

贈与分割

夫婦で贈与を2倍に分割できる選択

Gift splitting allows married couples to treat a gift as if each spouse gave half.

Present Interest

現在利益

受贈者が即時に享受できる利益。除外の要件

Only gifts of present interest qualify for the annual exclusion.

Taxable Estate

課税遺産額

Gross Estate - 控除（葬儀費、負債、配偶者控除等）

Taxable estate equals gross estate minus deductions for debts, expenses, and the marital deduction.

Step-Up in Basis

ステップアップ・ベイシス

相続財産のBasisが死亡日FMVに引き上げられる

Inherited property receives a stepped-up basis equal to its fair market value at the date of death.

Carryover Basis (Gift)

キャリーオーバー・ベイシス（贈与）

贈与財産は贈与者のBasisを引き継ぐ

The donee's basis in gifted property is generally the donor's adjusted basis (carryover basis).

Generation-Skipping Transfer Tax (GSTT)

世代飛越移転税

2世代以上下の者への移転に課される追加税

GSTT applies to transfers that skip a generation, such as a grandparent giving directly to a grandchild.

Portability

ポータビリティ

配偶者の未使用統一税額控除を引き継ぐ制度

Portability allows a surviving spouse to use the deceased spouse's unused exclusion amount.

Tuition/Medical Exclusion

学費・医療費の除外

直接支払いは贈与税の除外。年間除外額とは別枠

Tuition and medical expenses paid directly to the provider are excluded from gift tax without limit.

Alternate Valuation Date

代替評価日

死亡日の6ヶ月後の日を評価基準日に選択可能

The executor may elect the alternate valuation date if it reduces both the estate value and tax.

Revocable Trust

取消可能信託

設定者が取消可能。遺産税の対象

Assets in a revocable trust are included in the grantor's gross estate.

Traditional IRA

トラディショナルIRA

拠出時控除、引出時課税。RMD義務あり

Traditional IRA contributions may be tax-deductible, and withdrawals are taxed as ordinary income.

Roth IRA

ロスIRA

拠出時課税済、適格引出時非課税。RMDなし

Qualified distributions from a Roth IRA are tax-free because contributions were made with after-tax dollars.

Required Minimum Distribution (RMD)

最低引出義務

一定年齢以降の強制引出し。Traditional IRAに適用

RMDs require account holders to withdraw a minimum amount from retirement accounts each year.

401(k) Plan

401(k)プラン

雇用主提供の確定拠出型退職年金。税引前拠出

A 401(k) plan allows employees to contribute pre-tax income toward retirement savings.

529 Plan

529プラン

教育資金の税制優遇貯蓄プラン。運用益非課税

Earnings in a 529 plan grow tax-free if used for qualified education expenses.

Early Withdrawal Penalty

早期引出しペナルティ

59.5歳前の引出しに10%の追加税

A 10% penalty applies to early withdrawals from retirement accounts before age 59½.

Defined Benefit Plan (Tax)

確定給付型年金（税務）

雇用主が給付額を保証。拠出限度額が最大

A defined benefit plan provides a specified retirement benefit based on salary and years of service.

SEP IRA

SEP IRA

自営業者向けの簡易型退職年金

A SEP IRA allows self-employed individuals to contribute up to 25% of net self-employment income.

Health Savings Account (HSA)

医療貯蓄口座

高免責健康保険加入者向け。3重の税制優遇

HSA contributions are deductible, earnings grow tax-free, and qualified withdrawals are not taxed.

Coverdell Education Savings Account

カバーデル教育貯蓄口座

教育費用のための貯蓄口座。年間拠出限度あり

Coverdell accounts offer tax-free growth for qualified K-12 and higher education expenses.

Rollover

ロールオーバー

退職口座間の資金移動。60日以内で非課税

A rollover allows tax-free transfer of retirement funds between qualified plans within 60 days.

Tax-Deferred Growth

課税繰延成長

運用益に対する課税を引出時まで延期

Tax-deferred growth allows investments to compound without current taxation.

Pass-Through Entity

パススルー事業体

事業体レベルで課税されず、所有者に課税される

A partnership is a pass-through entity that does not pay income tax at the entity level.

Partner's Basis

パートナーのBasis

出資額 + 所得持分 + 負債持分 - 分配 - 損失持分

A partner's basis increases with income allocations and decreases with distributions and losses.

Guaranteed Payment

保証支払い

パートナーシップ利益に関係なく支払われる報酬

Guaranteed payments are deductible by the partnership and taxable as ordinary income to the partner.

Separately Stated Items

個別記載項目

パートナー個人の税額に影響する項目を個別に報告

Capital gains and charitable contributions are separately stated on Schedule K-1.

Schedule K-1

スケジュールK-1

パートナーの所得・損失等の配分報告書

Each partner receives a Schedule K-1 reporting their share of partnership income and deductions.

Nonrecourse Liability

ノンリコース負債

返済義務が担保資産に限定。Basis計算に影響

Nonrecourse liabilities are shared among partners for basis purposes based on profit-sharing ratios.

Recourse Liability

リコース負債

パートナーが個人的に返済義務を負う負債

Recourse liabilities are allocated to the partner who bears the economic risk of loss.

Liquidating Distribution

清算分配

パートナー持分の完全終了時の分配

In a liquidating distribution, the partner's basis in the partnership is reduced to zero.

Nonliquidating Distribution

通常分配

持分を維持しながらの分配。Basis超過分のみGain

Cash distributions exceeding the partner's basis result in capital gain recognition.

Section 704(b) Allocation

§704(b)配分

特別配分は経済的実体が必要

Special allocations must have substantial economic effect to be respected for tax purposes.

Hot Assets (§751)

ホットアセット（§751）

未実現売掛金・棚卸資産。売却時にOrdinary Income

Hot assets include unrealized receivables and inventory that convert capital gain to ordinary income.

Inside Basis vs Outside Basis

インサイドBasis vs アウトサイドBasis

Inside=パートナーシップ内の資産Basis、Outside=パートナーの持分Basis

Inside basis refers to the partnership's basis in its assets; outside basis is each partner's basis in their interest.

Contribution to Partnership

パートナーシップへの拠出

原則非課税。拠出者のBasisをキャリーオーバー

Contributing property to a partnership is generally a nontaxable event.

Form 1065

フォーム1065

パートナーシップの情報申告書

Partnerships file Form 1065 as an information return but do not pay entity-level tax.

Substantial Economic Effect

実質的な経済的効果

特別配分が認められるための要件

An allocation must affect dollar amounts received by partners to have substantial economic effect.

Section 754 Election

§754選択

持分譲渡時のInside Basisの任意調整

A Section 754 election adjusts the partnership's inside basis when a partner's interest is transferred.

Partnership Agreement

パートナーシップ契約

利益・損失の配分等を定めた契約書

The partnership agreement governs how income, losses, and distributions are allocated among partners.

Organizational Costs

設立費用

最初の$5,000は即時費用化、残りは180ヶ月で償却

Up to $5,000 of organizational costs may be deducted immediately, with the remainder amortized over 180 months.

Double Taxation

二重課税

法人レベルで法人税、株主レベルで配当税

C corporations face double taxation: corporate income tax on earnings and shareholder tax on dividends.

Earnings and Profits (E&P)

利益積立金

配当の原資を測定する税務上の概念

Distributions are taxable dividends to the extent of current and accumulated E&P.

Section 351 (Nonrecognition)

§351（非課税組入れ）

80%支配要件を満たせば法人設立時に非課税

Under Section 351, no gain is recognized if transferors control 80% or more of the corporation.

Dividends Received Deduction (DRD)

受取配当金控除

法人が受け取る配当の50/65/100%を控除

The DRD allows corporations to deduct a percentage of dividends received from other corporations.

Accumulated Earnings Tax

累積利益税

配当を不合理に留保した場合のペナルティ税

The accumulated earnings tax penalizes corporations that retain earnings beyond reasonable business needs.

Personal Holding Company (PHC) Tax

人的持株会社税

少数株主の投資所得会社へのペナルティ税

A PHC tax applies to closely held corporations with excessive passive income.

Corporate Capital Loss

法人の資本損失

資本利益のみと相殺可能。通常所得と相殺不可

Corporate capital losses can only offset capital gains, with a 3-year carryback and 5-year carryforward.

Charitable Contribution Limit (Corp)

法人の寄付金控除限度額

課税所得の10%が上限

A corporation's charitable contribution deduction is limited to 10% of taxable income.

Schedule M-1 / M-3

スケジュールM-1 / M-3

帳簿利益と課税所得の差異調整表

Schedule M-1 reconciles book income to taxable income, showing permanent and temporary differences.

Constructive Dividend

推定配当

正式な配当宣言なしに株主が受ける経済的利益

An excessive salary paid to a shareholder-employee may be reclassified as a constructive dividend.

Form 1120

フォーム1120

C Corporationの法人税申告書

C corporations file Form 1120 to report income, deductions, and tax liability.

Flat Corporate Tax Rate

法人税の均一税率

21%のフラットレート（TCJA以降）

C corporations are taxed at a flat 21% rate on their taxable income.

Boot (§351)

ブート（§351）

§351取引で受け取る株式以外の対価。Gain認識

Boot received in a Section 351 exchange triggers gain recognition to the extent of boot received.

Current E&P vs Accumulated E&P

当期E&P vs 累積E&P

当期E&P優先で配当判定。両方なければReturn of Capital

Distributions are treated as dividends first from current E&P, then from accumulated E&P.

Complete Liquidation

完全清算

法人解散時の資産分配。FMVでGain/Loss認識

In a complete liquidation, the corporation recognizes gain or loss as if assets were sold at FMV.

Section 332 Liquidation

§332清算（親子間）

80%以上子会社の清算は親会社で非課税

Section 332 provides nonrecognition treatment for a parent liquidating an 80%-owned subsidiary.

Redemption

株式償還

自社株買い。配当か資本取引かの判定が重要

A stock redemption may be treated as a sale or exchange if it meets certain tests.

Related Party Rules (§267)

関連者取引ルール（§267）

関連者間の損失の否認。50%超の所有関係

Losses on sales between related parties are disallowed under Section 267.

S Corporation Election

S Corporation選択

全株主の同意が必要。Form 2553で選択

S corporation status requires the unanimous consent of all shareholders filed on Form 2553.

S Corp Eligibility

S Corp適格要件

100人以下、1クラス株式、適格株主のみ

An S corporation must have no more than 100 shareholders and only one class of stock.

Shareholder Basis (S Corp)

株主Basis（S Corp）

C Corpと異なり所得・損失で増減。負債は含まない

S corporation shareholder basis is increased by income and decreased by distributions and losses.

Built-in Gains Tax (BIG Tax)

ビルトイン・ゲイン税

C→S転換後5年以内の含み益売却に法人税

The built-in gains tax applies when an S corp sells assets with gains built in during C corp years.

Accumulated Adjustments Account (AAA)

累積調整勘定

S Corp期間の税引後利益の累積。分配の優先原資

AAA tracks S corporation earnings that have already been taxed to shareholders.

Excess Net Passive Income Tax

過大受動的純所得税

C Corp時代のE&PがありPassive Income > 25%の場合

An S corp with accumulated E&P is subject to tax if passive income exceeds 25% of gross receipts.

Termination of S Election

S Corp選択の終了

適格要件違反、自主的取消、Passive Income超過3年連続

S corporation status is terminated if eligibility requirements are no longer met.

S Corp vs Partnership Comparison

S Corpとパートナーシップの比較

主な違い: 株式クラス制限、負債のBasis算入、特別配分

Unlike partnerships, S corporations cannot have special allocations or multiple classes of stock.

Reasonable Compensation (S Corp)

合理的報酬（S Corp）

株主従業員への適正な給与。自営業税の論点

S corp shareholder-employees must receive reasonable compensation subject to employment taxes.

Form 1120-S

フォーム1120-S

S Corporationの情報申告書

S corporations file Form 1120-S as an information return and issue K-1s to shareholders.

Fringe Benefits (S Corp)

付加給付（S Corp）

2%超株主は個人事業主と同様の扱い

Health insurance premiums for a 2% shareholder are deductible by the S corp but taxable to the shareholder.

Debt Basis (S Corp vs Partnership)

負債Basis（S Corp vs Partnership）

S Corpは直接の株主貸付のみ。Partnershipは共有負債も含む

S corp shareholders only get basis from direct loans to the corporation, not from entity-level debt.

Distribution Ordering (S Corp)

分配の適用順序（S Corp）

AAA → AEP → Other → Stockの順に適用

S corp distributions come first from AAA (tax-free), then from accumulated E&P (taxable dividend).

Character Preservation

所得の性格維持

パススルー時に所得の種類が維持される

Capital gains retain their character when passed through to S corporation shareholders.

One Class of Stock Rule

1クラス株式ルール

全株式の配当・清算権は同一でなければならない

S corporations may only have one class of stock, though voting rights may differ.

Entity Selection

事業体選択

Sole Prop, Partnership, LLC, S Corp, C Corpの比較

Entity selection considers factors like liability protection, taxation, and ease of formation.

80% Control Test (§351)

80%支配テスト（§351）

法人への財産拠出が非課税となる支配要件

Transferors must control at least 80% of the corporation's stock immediately after the exchange.

Check-the-Box Regulations

チェック・ザ・ボックス規則

事業体の税務分類を選択する制度

An LLC can elect to be taxed as a partnership, C corporation, or S corporation.

Limited Liability Company (LLC)

合同会社（LLC）

有限責任 + パススルー課税の柔軟な事業体

An LLC provides limited liability protection while allowing pass-through taxation.

Sole Proprietorship

個人事業

最も簡単な事業形態。Schedule Cで申告

A sole proprietorship reports business income on Schedule C of the owner's individual return.

Self-Employment Tax

自営業税

Social Security + Medicare税。個人事業主が負担

Self-employment tax covers Social Security and Medicare taxes for self-employed individuals.

Section 721 (Partnership Formation)

§721（パートナーシップ設立）

パートナーシップへの拠出は原則非課税

Section 721 provides nonrecognition treatment for property contributed to a partnership.

Section 1244 Stock

§1244株式

小規模法人株式の損失をOrdinary Lossで控除可能

Section 1244 allows individual shareholders to deduct losses on qualifying stock as ordinary losses.

Section 1202 (QSBS)

§1202（適格小規模企業株式）

5年以上保有で売却益の最大100%非課税

Section 1202 excludes up to 100% of gain on qualified small business stock held for more than 5 years.

Tax Year Selection

課税年度の選択

パートナーシップ・S Corpは暦年が原則

Partnerships and S corporations generally must use a calendar year unless they can establish a business purpose.

Accounting Method Selection

会計方法の選択

Cash, Accrual, Hybrid。規模・業種で制限あり

Most small businesses can use the cash method, but certain corporations must use the accrual method.

Liquidation vs Dissolution

清算 vs 解散

清算=資産分配、解散=法的終了

Liquidation involves distributing assets to owners, while dissolution is the legal termination of the entity.

General Partner vs Limited Partner

ゼネラルパートナー vs リミテッドパートナー

GP=無限責任+経営参加、LP=有限責任+経営不参加

General partners have unlimited liability and manage the business; limited partners have limited liability.

Section 338 Election

§338選択

株式取得を資産取得として扱う選択

A Section 338 election treats a stock purchase as an asset purchase for tax purposes.

Type A/B/C Reorganization

A/B/C型組織再編

非課税の企業再編。合併、株式交換、資産取得

Tax-free reorganizations include statutory mergers (Type A), stock acquisitions (Type B), and asset acquisitions (Type C).

Distributable Net Income (DNI)

分配可能純所得

信託/遺産から受益者への所得配分の上限

DNI limits the amount of income that can be taxed to the beneficiary.

Simple Trust

単純信託

所得を全額分配。元本の分配なし。寄付なし

A simple trust must distribute all income currently and may not make charitable contributions.

Complex Trust

複合信託

所得の留保、元本の分配、寄付が可能

A complex trust may accumulate income, distribute principal, or make charitable contributions.

Grantor Trust

グランター信託

設定者が課税される信託。取消可能信託が典型

In a grantor trust, the grantor is taxed on the trust income as if the trust did not exist.

Income Distribution Deduction

所得分配控除

信託が受益者に分配した所得の控除。DNIが上限

The trust deducts distributions to beneficiaries, limited to DNI, to avoid double taxation.

Trust Accounting Income (TAI)

信託会計所得

信託契約・州法に基づく所得概念

Trust accounting income determines what must be distributed and is defined by the trust document.

Fiduciary Income Tax Return (Form 1041)

受託者所得税申告書

信託・遺産の所得税申告書

Trusts and estates file Form 1041 to report income and claim the income distribution deduction.

Compressed Tax Brackets

圧縮税率表

信託・遺産は低額で最高税率に到達

Trusts reach the top marginal tax rate at much lower income levels than individuals.

Tier System (Distributions)

ティアシステム（分配）

Tier 1=必須分配、Tier 2=裁量分配。課税順序

Tier 1 distributions (required) are taxed before Tier 2 distributions (discretionary).

Personal Exemption (Trust/Estate)

人的控除（信託/遺産）

Simple trust=$300、Complex trust=$100、Estate=$600

The personal exemption for a simple trust is $300; for a complex trust, it is $100.

Throwback Rule

スローバックルール

過年度の留保所得分配に対する追加課税

The throwback rule taxes accumulated income distributed in later years.

65-Day Rule

65日ルール

年度末後65日以内の分配を前年度扱いにする選択

The 65-day rule allows distributions made within 65 days of year-end to be treated as prior-year distributions.

Section 501(c)(3) Organization

§501(c)(3)組織

慈善・教育・宗教目的の非課税組織

Section 501(c)(3) organizations are exempt from federal income tax and can receive tax-deductible donations.

Unrelated Business Taxable Income (UBTI)

非関連事業課税所得

非課税組織の本来目的外の事業所得。課税対象

UBTI from a trade or business regularly carried on and unrelated to the exempt purpose is taxable.

Controlled Foreign Corporation (CFC)

被支配外国法人

米国株主が50%超を所有する外国法人

A CFC's Subpart F income is taxed to U.S. shareholders regardless of whether it is distributed.

GILTI (Global Intangible Low-Taxed Income)

グローバル無形資産低課税所得

CFCの超過利益を米国株主に課税

GILTI requires U.S. shareholders to include CFC income exceeding a deemed return on tangible assets.

Foreign Tax Credit

外国税額控除

外国で支払った税金を米国税から控除

The foreign tax credit prevents double taxation by allowing a credit for taxes paid to foreign governments.

Subpart F Income

サブパートF所得

CFCの受動的所得等。配当前でも米国株主に課税

Subpart F income includes passive income like dividends, interest, and rents earned by a CFC.

FDII (Foreign-Derived Intangible Income)

外国由来無形資産所得

米国法人の輸出関連超過利益に優遇税率

FDII provides a deduction for U.S. corporations on income derived from serving foreign markets.

BEAT (Base Erosion Anti-Abuse Tax)

税源浸食濫用防止税

大企業の国外関連者への過大支払いに対する最低税

BEAT ensures that large corporations pay a minimum tax by adding back deductible payments to foreign affiliates.

Private Foundation

私的財団

Public charityでない§501(c)(3)。追加規制あり

Private foundations face additional restrictions including excise taxes on investment income.

Nexus (State Tax)

ネクサス（州税の課税根拠）

州が課税権を行使するための最低限の接点

Physical presence or economic activity in a state creates nexus for state tax purposes.

Transfer Pricing

移転価格税制

関連者間取引は独立企業間価格で行う義務

Transfer pricing rules require related-party transactions to be conducted at arm's length.

Form 990

フォーム990

非課税組織の情報申告書

Tax-exempt organizations file Form 990 annually to report financial information to the IRS.

Like-Kind Exchange (§1031)

同種交換

不動産の交換で損益を繰延べ。Boot受領分のみ課税

Section 1031 allows deferral of gain on the exchange of like-kind real property.

Section 1231 Property

§1231資産

事業用資産。Net gain=LTCG、Net loss=Ordinary

Section 1231 provides favorable treatment: net gains are taxed as LTCG, net losses as ordinary.

Section 1245 Recapture

§1245再捕捉

動産の減価償却累計額をOrdinary Incomeとして再捕捉

Section 1245 recaptures all depreciation taken on personal property as ordinary income upon sale.

Section 1250 Recapture

§1250再捕捉

不動産の加速償却超過分をOrdinary Incomeとして再捕捉

Section 1250 recaptures excess depreciation on real property as ordinary income.

Involuntary Conversion (§1033)

非自発的買換（§1033）

災害等による資産の消滅。類似資産に再投資で繰延べ

Section 1033 defers gain from involuntary conversions if the proceeds are reinvested in similar property.

Installment Sale (§453)

分割売買（§453）

代金を分割受領。収益を各年度に按分認識

An installment sale allows the seller to recognize gain proportionally as payments are received.

Gross Profit Percentage

総利益率

Installment saleで各回の収入に乗じてGain計算

The gross profit percentage is used to determine the taxable portion of each installment payment.

Boot (§1031)

ブート（§1031）

同種交換で受け取る非同種資産。受領Boot分のGain認識

Cash or non-like-kind property received in a Section 1031 exchange is boot that triggers gain.

Adjusted Basis

調整後Basis

取得原価 + 改良 - 減価償却。Gain/Loss計算の基礎

Adjusted basis equals the original cost plus improvements minus accumulated depreciation.

Holding Period

保有期間

1年超=Long-term、1年以下=Short-term

Assets held for more than one year qualify for long-term capital gain tax rates.

Section 121 Exclusion

§121除外（居住用不動産）

主たる住居の売却益を最大$250K/$500K除外

Section 121 excludes up to $250,000 ($500,000 MFJ) of gain from the sale of a principal residence.

Unrecaptured Section 1250 Gain

未再捕捉§1250利益

不動産の定額償却分のCG。最大25%で課税

Unrecaptured Section 1250 gain on real property is taxed at a maximum rate of 25%.

Wash Sale Rule

ウォッシュセールルール

売却前後30日以内に同一証券を購入すると損失否認

The wash sale rule disallows a loss if substantially identical securities are acquired within 30 days.

Depreciation Recapture

減価償却の再捕捉

過去の減価償却をOrdinary Incomeとして取り戻す

Depreciation recapture converts a portion of gain on sale from capital to ordinary income.

Related Party Sale (§267)

関連者間売却（§267）

関連者間の損失は否認。利益は認識

Losses on sales between related parties are disallowed; gains are recognized.

Net Investment Income Tax (NIIT)

純投資所得税

高所得者の投資所得に3.8%の追加税

The 3.8% NIIT applies to investment income for individuals with MAGI above the threshold.

Qualified Opportunity Zone

適格機会特区

CG再投資で課税繰延べ・10年保有で新規Gain非課税

Investing capital gains in a qualified opportunity zone fund can defer and reduce capital gains taxes.

Section 1231 Lookback Rule

§1231ルックバックルール

過去5年のOrdinary Loss分だけ当期Net GainをOrdinaryに

The Section 1231 lookback rule recharacterizes current gains as ordinary to the extent of prior ordinary losses.