12.3 Entity-Level Taxes (BIG §1374 & Passive Income §1375) & Termination

Entity-Level Taxation of S Corporations: Historical Context & Purpose

Under IRC §1363(a), an S corporation is fundamentally a pass-through entity that is exempt from federal income taxation. However, Congress enacted statutory exceptions to prevent corporations from using Subchapter S as a tax-avoidance vehicle to escape double taxation on earnings and asset appreciation accumulated while operating as a C corporation.

On the Special Enrollment Examination Part 2, candidates must master the three entity-level corporate taxes that can apply to S corporations:

1. The Built-In Gains (BIG) Tax under IRC §1374;
2. The Excess Net Passive Income (ENPI) Tax under IRC §1375; and
3. The LIFO Recapture Tax under IRC §1363(d).

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Built-In Gains (BIG) Tax (IRC §1374)

The Built-In Gains (BIG) Tax was enacted to prevent C corporations with substantially appreciated assets from electing S corporation status immediately prior to selling those assets, thereby attempting to convert double taxation into a single-layer pass-through gain.

The 5-Year Recognition Period

Under IRC §1374(d)(7), the BIG tax applies to any Net Recognized Built-In Gain (NRBIG) recognized by a former C corporation during a 5-year recognition period beginning on the very first day of the first taxable year for which the S corporation election is effective. If an asset is sold on or after the day following the 5-year anniversary, no §1374 tax applies.

Net Unrealized Built-In Gain (NUBIG) Ceiling

On the effective date of the S election, the corporation must perform a mandatory valuation of all corporate assets (including goodwill, intangibles, and cash-basis accounts receivable):

$\text{Net Unrealized Built-In Gain (NUBIG)} = \text{Aggregate FMV of All Assets} - \text{Aggregate Adjusted Tax Basis of All Assets}$

NUBIG establishes an absolute cumulative lifetime ceiling on the aggregate amount of built-in gain that can ever be taxed under §1374 over the entire 5-year recognition period.

Computing Net Recognized Built-In Gain (NRBIG)

In each year of the 5-year window, the corporation calculates its Net Recognized Built-In Gain (NRBIG), which is the LEAST of three statutory amounts under IRC §1374(d)(2):

$\text{NRBIG} = \min(\text{Pre-Limitation NRBIG}, \text{Taxable Income Limitation}, \text{Remaining NUBIG})$

1. Pre-Limitation NRBIG: Recognized built-in gains during the year minus recognized built-in losses during the year. (Recognized gain on an asset is capped at the excess of FMV over basis on Day 1 of S status; post-conversion appreciation is exempt from BIG tax).
2. Taxable Income Limitation: The corporation's taxable income computed as if it were a C corporation under IRC §11, but without claiming the net operating loss deduction (NOL under §172) or the dividends-received deduction (DRD under §243).
3. Remaining NUBIG Limitation: The original NUBIG minus all NRBIG taxed in prior years.

The Taxable Income Carryover Rule

If NRBIG is reduced by the taxable income limitation, the unabsorbed excess gain is carried forward and treated as recognized built-in gain in the subsequent taxable year, provided the subsequent year falls within the 5-year recognition period (IRC §1374(d)(2)(B)).

Tax Calculation and Pass-Through to Shareholders

• Corporate Tax Rate: NRBIG is taxed at the highest corporate tax rate specified in IRC §11(b), which is a flat 21%.
• Corporate Attribute Offsets: The S corporation may offset NRBIG with unexpired C corporation Net Operating Loss (NOL) carryforwards and business credit carryforwards generated prior to the S election (IRC §1374(b)).
• Shareholder Flow-Through (§1366(f)(2)): The BIG tax paid by the S corporation is treated as a loss sustained by the S corporation during the tax year. It passes through to shareholders on Schedule K-1 with the same tax character as the underlying gain (e.g., long-term capital loss, §1231 loss, or ordinary loss), directly reducing the net taxable gain passed through to shareholders.

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Excess Net Passive Income (ENPI) Tax (IRC §1375)

Under IRC §1375, an entity-level corporate tax is imposed on an S corporation's Excess Net Passive Income when two statutory prerequisites occur simultaneously at the close of the tax year:

IRC §1375 Dual Statutory Prerequisites
  ├── Condition 1: S corporation has Accumulated C Corporation E&P at year-end
  └── Condition 2: Passive Investment Income (PII) exceeds 25% of Corporate Gross Receipts

Definition of Passive Investment Income (PII)

Under IRC §1362(d)(3)(C), passive investment income includes gross receipts derived from:

• Royalties, rents, dividends, interest, annuities, and gains from the sale or exchange of stock or securities.
• Exceptions: Does not include active business rents (where significant personal services or substantial operational costs are provided) or interest earned on notes receivable from inventory sales in the ordinary course of business.

The Statutory ENPI Allocation Formula

If the 25% threshold is breached and C corp E&P exists, the taxable Excess Net Passive Income (ENPI) is computed using the mandatory statutory formula under IRC §1375(b)(1):

$\text{ENPI} = \text{Net Passive Income (NPI)} \times \left[ \frac{\text{Passive Investment Income (PII)} - (25\% \times \text{Gross Receipts})}{\text{Passive Investment Income (PII)}} \right]$

Where:

• Net Passive Income (NPI): Passive investment income reduced by allowable deductions directly connected with producing the passive income (e.g., property taxes, depreciation, investment advisory fees).
• Limitation: ENPI cannot exceed the corporation's taxable income computed under C corporation rules without NOL or special deductions.

Tax Rate and Shareholder Pass-Through

• Tax Rate: ENPI is taxed at the flat corporate rate of 21%.
• Shareholder Reduction (§1366(f)(3)): The §1375 tax paid by the S corporation reduces the passive investment income passed through to shareholders pro-rata on Schedule K-1, preventing double taxation of the penalized income.

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LIFO Recapture Tax (IRC §1363(d))

When a C corporation that maintains inventory under the LIFO (Last-In, First-Out) method elects S corporation status, it must pay a LIFO Recapture Tax under IRC §1363(d).

• The LIFO Reserve: The recapture amount equals the excess of inventory value computed under FIFO (First-In, First-Out) over the inventory's adjusted basis under LIFO at the close of the C corporation's final tax year.
• Inclusion in Income: The entire LIFO reserve is included in gross income on the final Form 1120 of the C corporation.
• The Four-Year Installment Rule: The resulting tax liability is payable in four equal, annual installments:
  • 1st Installment: Due on or before the due date (without extensions) of the final C corporation return.
  • 2nd, 3rd, and 4th Installments: Due on or before the due dates (without extensions) of the S corporation's returns for the next three consecutive tax years.
  • No interest is charged if installments are paid timely.
• Basis Step-Up: The S corporation increases the tax basis of its opening inventory by the full amount of the recaptured LIFO reserve.

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S Corporation Termination under IRC §1362(d)

An S corporation election remains in effect until formally terminated. Termination can occur through three distinct statutory mechanisms under IRC §1362(d):

1. Voluntary Revocation (IRC §1362(d)(1))

An S corporation may voluntarily revoke its S election by filing a statement of revocation with the IRS Service Center where the election was filed.

• Voting Threshold: Must be consented to by shareholders who hold more than 50% of the total number of issued and outstanding shares of stock (including nonvoting common stock!).
• Effective Date:
  • If revocation is filed on or before the 15th day of the 3rd month of the tax year (March 15 for a calendar year entity), it can be made retroactive to the first day of that tax year (January 1).
  • If filed after the 15th day of the 3rd month, it is effective on the first day of the following tax year, unless the revocation specifies a prospective effective date on or after the filing date.

2. Involuntary Termination: Loss of Eligibility (IRC §1362(d)(2))

An S election terminates immediately on the exact day that the corporation ceases to qualify as a small business corporation under IRC §1361(b):

• Exceeding the 100-shareholder limit.
• Transferring shares to an ineligible shareholder (such as a C corporation, partnership, LLC, or nonresident alien individual).
• Creating a prohibited second class of stock (differing rights to distributions or liquidation proceeds).
• Acquiring an ineligible corporate status (e.g., insurance company or domestic international sales corporation).

The S Termination Year: The tax year in which an involuntary disqualification occurs is split into two short tax years: an S short year (from Jan 1 through the day prior to termination) and a C short year (from the termination date through Dec 31). Corporate income and deductions are allocated between the two short years pro-rata based on daily ownership, or by closing the books if all affected shareholders consent (IRC §1362(e)).

3. Involuntary Termination: The Three-Year Passive Income Rule (IRC §1362(d)(3))

An S corporation election is automatically terminated if the corporation meets two conditions for three consecutive taxable years:

1. It has accumulated C corporation E&P at the close of each of the three consecutive years; AND
2. More than 25% of its gross receipts for each of those three consecutive years consists of passive investment income.

[!CRITICAL] Effective Date of Passive Income Termination: The termination is NOT retroactive to the first year, nor is it effective in the third year. The termination becomes effective on the first day of the fourth taxable year!

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The 5-Year Re-Election Bar & Inadvertent Termination Relief

• The 5-Year Waiting Period (IRC §1362(g)): Once an S election is terminated or revoked, the corporation (and any successor corporation) is prohibited from re-electing S status for five taxable years without the express consent of the IRS Commissioner.
• Inadvertent Termination Relief (IRC §1362(f)): If an S election was terminated inadvertently (e.g., an accountant discovered that stock was mistakenly transferred to an ineligible trust, or the 3-year passive income rule was breached unintentionally), the IRS will treat the corporation as continuing to be an S corporation provided that:
  1. The IRS determines that the termination was inadvertent;
  2. The corporation takes immediate steps within a reasonable period to correct the disqualifying condition (e.g., repurchasing the ineligible stock); and
  3. The corporation and all shareholders agree to make any adjustments required by the IRS.

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The Post-Termination Transition Period (PTTP) (IRC §1377(b))

When an S corporation terminates its election and converts into a C corporation, shareholders are granted a statutory grace period known as the Post-Termination Transition Period (PTTP) under IRC §1377(b).

Duration of the PTTP

The PTTP generally begins on the day after the last day of the corporation's final S corporation year and ends on the later of:

• One year after the effective date of termination; OR
• The due date (including extensions) for filing the final Form 1120-S return.

Two Vital Tax Benefits during the PTTP

1. Tax-Free Cash Distributions of AAA (IRC §1371(e)): During the PTTP, cash distributions made by the newly converted C corporation to shareholders are treated as tax-free returns of basis to the extent of the corporation's undistributed Accumulated Adjustments Account (AAA) balance earned during S years, reducing stock basis. (Property distributions do not qualify; distributions must be in cash!).
2. Deduction of Suspended Losses (IRC §1366(d)(3)): Any shareholder losses suspended due to lack of basis at the time of S termination can be deducted on the final day of the PTTP to the extent of any new stock basis created by the shareholder through capital contributions during the PTTP.

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Comprehensive Worked Numerical Examples

Worked Example 1: Built-In Gains (BIG) Tax Calculation (§1374)

Scenario: Ironclad Inc. converted from a C corporation to an S corporation effective January 1, 2023. On January 1, 2023, Ironclad held:

• Commercial Land: Tax basis = $100,000; FMV = $250,000 (Built-in gain = $150,000).
• Heavy Machinery: Tax basis = $80,000; FMV = $50,000 (Built-in loss = -$30,000).
• Net Unrealized Built-In Gain (NUBIG) Ceiling: $150,000 - $30,000 = $120,000.

In 2025 (Year 3 of the 5-year recognition period), Ironclad sells the commercial land for $260,000.

• Total gain recognized = $260,000 - $100,000 = $160,000.
• Recognized Built-In Gain (RBIG) is capped at the pre-conversion gain: $150,000 (the extra $10,000 post-conversion gain is exempt from BIG tax).
• Ironclad recognized $0 built-in losses in 2025.
• Remaining NUBIG = $120,000 (caps RBIG at $120,000).
• In 2025, Ironclad's corporate taxable income computed under C corporation rules is $90,000 (the Taxable Income Limitation).

Tax Computation:

1. Net Recognized Built-In Gain (NRBIG): Lesser of $120,000 NUBIG limit or $90,000 Taxable Income Limit = $90,000.
2. Corporate BIG Tax: $90,000 × 21% = $18,900.
3. Taxable Income Carryover: The unabsorbed built-in gain of $120,000 - $90,000 = $30,000 carries forward to 2026 and 2027 (remaining recognition window).
4. Shareholder Pass-Through (§1366(f)(2)): The $18,900 BIG tax paid is treated as a long-term capital loss that offsets the $160,000 gain. Net capital gain passed through to shareholders on Schedule K-1 is $160,000 - $18,900 = $141,100.

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Worked Example 2: Excess Net Passive Income (ENPI) Tax (§1375)

Scenario: Meridian Properties, Inc. is an S corporation that has $50,000 of Accumulated C corp E&P at the close of 2025. In 2025, Meridian reports:

• Gross Receipts: $400,000
• Passive Investment Income (gross rents and dividends): $160,000
• Allowable expenses directly connected to passive income: $40,000

Step-by-Step Calculation:

1. Test the 25% Threshold:
   • 25% of Gross Receipts = 25% × $400,000 = $100,000.
   • Passive Investment Income ($160,000) exceeds $100,000. Because C corp E&P exists, §1375 applies.
2. Compute Net Passive Income (NPI):
   • NPI = $160,000 (PII) - $40,000 (Direct expenses) = $120,000.
3. Compute Excess Net Passive Income (ENPI):
   • ENPI = $120,000 × [($160,000 - $100,000) / $160,000] = $120,000 × ($60,000 / $160,000) = $120,000 × 0.375 = $45,000.
4. Calculate Entity-Level Corporate Tax:
   • Tax Liability = $45,000 × 21% = $9,450.
5. Shareholder Pass-Through Impact (§1366(f)(3)): The $9,450 corporate tax paid reduces the passive income passed through to shareholders on Schedule K-1.

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Comparison Table: Entity-Level Corporate Taxes on S Corporations