Overview

The S Corporation Modernization Act of 2025 is a comprehensive reform of the federal tax rules governing S corporations under the Internal Revenue Code of 1986. The bill addresses longstanding structural limitations of the S corporation regime by expanding shareholder eligibility, modernizing passive investment income rules, creating new mechanisms for handling built-in gains upon shareholder death, establishing withholding tax obligations for nonresident alien shareholders, and addressing the transfer of suspended losses at death. The legislation reflects a broad effort to make S corporations more competitive and flexible as a business entity choice, particularly for closely held businesses, while also bringing nonresident alien participation into a structured compliance framework. The bill touches nearly every major aspect of S corporation taxation, from eligibility and income characterization to basis adjustments, deferred compensation, and estate planning considerations.

Key Points

• Expands S corporation eligible shareholders to include IRAs and nonresident alien individuals
• Creates a new deduction mechanism for built-in gains upon shareholder death, amortized over 15 years
• Raises the passive investment income threshold from 25 percent to 60 percent and repeals excessive passive income as a termination event
• Establishes a new withholding tax regime for nonresident alien shareholders under new IRC Section 1447
• Allows transfer of suspended losses incident to the death of a shareholder
• Addresses nonqualified deferred compensation plan treatment in the S corporation context

Legal References

• Internal Revenue Code of 1986
• S Corporation Modernization Act of 2025 (S. 2017)

Core Provisions

The bill's most structurally significant change is the creation of new IRC Section 1369, which governs the treatment of S corporation built-in gain amounts upon the death of a shareholder. Under this provision, a person who acquires S corporation stock with a basis determined under Section 1014(a) — that is, a stepped-up basis at death — is allowed a deduction with respect to the amortizable S corporation built-in gain amount. This deduction is amortized over a 15-year period beginning with the month that includes the applicable valuation date, which is the date of the shareholder's death. The provision distinguishes between amortizable S corporation built-in gain property, which is subject to depreciation or amortization, and non-amortizable S corporation built-in gain property, which is not. For dispositions of non-amortizable property, the deduction available in the year of disposition is increased by the lesser of specified amounts, providing an accelerated recognition mechanism tied to actual asset sales. The S corporation built-in gain amount itself is defined as the lesser of the step-up in basis of the stock under Section 1014(a) or the pro rata share of built-in gain attributable to non-amortizable property as of the valuation date. An S corporation may elect into this regime, and the Secretary prescribes the time and form for such elections. The bill amends Section 1366(d)(2)(B) to allow suspended losses of S corporation shareholders to be transferred incident to the death of the transferor, effective for taxable years beginning after December 31, 2025. Previously, suspended losses were generally lost at death; this amendment aligns the treatment of suspended losses with the broader estate planning reforms in the bill. New IRC Section 1447 establishes a withholding tax on nonresident alien S corporation shareholders' pro rata share of effectively connected taxable income. The withholding tax equals the product of the highest individual tax rate under Section 1 and the aggregate pro rata shares of effectively connected taxable income allocable to nonresident alien shareholders. Nonresident alien shareholders are allowed a credit under Section 33 for their share of the withholding tax paid by the S corporation. The Secretary is authorized to provide exceptions and special rules, including rules for withholding on dispositions of S corporation stock, with cross-references to the partnership withholding rules under Section 1446(f). Section 1361 is amended to expand eligible S corporation shareholders to include trusts constituting individual retirement accounts under Section 408(a), including Roth IRAs under Section 408A, and nonresident alien individuals. A conforming provision treats all employees and their estates of a corporation and its wholly owned business entities as a single shareholder for purposes of the 100-shareholder limit under Section 1361(b)(1)(A). The passive investment income rules under Section 1375 are substantially liberalized. The income threshold triggering the passive investment income tax is raised from 25 percent to 60 percent of gross receipts, and the provision under Section 1362(d)(3) that treated excessive passive income as a ground for involuntary termination of S corporation status is repealed entirely. An exception is also created for banks and depository institution holding companies. The definition of passive investment income under Section 1375 continues to encompass royalties, rents, dividends, interest, and annuities. The bill also addresses nonqualified deferred compensation by amending Section 457A(e) to strike paragraph (5), effectively repealing the inclusion in gross income of deferred compensation under certain nonqualified deferred compensation plans in the S corporation context. Conforming amendments clarify that arrangements permitting employees to receive qualified stock and defer recognition under Section 83(i) are not treated as nonqualified deferred compensation plans solely on that basis.

Key Points

• New §1369: 15-year amortization deduction for built-in gains upon shareholder death, with accelerated deduction on disposition of non-amortizable property
• Amendment to §1366(d)(2)(B): suspended losses transferable at death, effective taxable years beginning after December 31, 2025
• New §1447: withholding tax on nonresident alien shareholders' effectively connected income at highest Section 1 rate
• Amendment to §1361: IRAs and nonresident alien individuals added as eligible S corporation shareholders
• Amendment to §1375(a)(2): passive investment income threshold raised from 25% to 60%
• Repeal of §1362(d)(3): excessive passive income no longer a termination event
• Amendment to §457A(e): repeal of gross income inclusion for certain nonqualified deferred compensation

Legal References

• IRC § 1361
• IRC § 1362(d)(3)
• IRC § 1366(d)(2)(B)
• IRC § 1367
• IRC § 1369 (new)
• IRC § 1374
• IRC § 1375
• IRC § 1446(f)
• IRC § 1447 (new)
• IRC § 408(a)
• IRC § 408A
• IRC § 457A(e)
• IRC § 83(i)
• IRC § 1014(a)
• IRC § 6037

Implementation

Primary implementation responsibility rests with the Secretary of the Treasury and the Internal Revenue Service. The Secretary is granted broad regulatory authority throughout the bill to prescribe regulations and guidance necessary to carry out each major provision. For the built-in gain death treatment under Section 1369, the Secretary must establish election procedures, aggregation rules, and basis adjustment mechanics. For the withholding tax under Section 1447, the Secretary must issue guidance on aggregation rules, basis adjustments to S corporation stock, exceptions to withholding, and special rules for dispositions of S corporation stock, drawing by analogy on the existing partnership withholding framework under Section 1446(f). Reporting obligations are centralized through Section 6037, which governs S corporation returns. The bill requires that pro rata share amounts determined under specified subsections of Section 1369 be treated as items of the corporation and furnished to shareholders through the Section 6037(b) reporting process. This integrates the new built-in gain deduction mechanics into the existing S corporation information reporting infrastructure. The bill establishes staggered effective dates that create a phased compliance timeline. The built-in gain death treatment under Section 1369 applies to decedents dying after the date of enactment in taxable years ending after that date. The suspended loss transfer amendment and passive investment income modifications apply to taxable years beginning after December 31, 2025. The nonresident alien shareholder expansion and related withholding provisions under Section 1447 apply to taxable years beginning after December 31, 2024. The nonqualified deferred compensation amendments also apply to taxable years beginning after December 31, 2024. S corporations must comply with withholding tax obligations on an ongoing basis, with nonresident alien shareholders claiming credits on their individual returns under Section 33.

Key Points

• Secretary of the Treasury has broad regulatory authority to issue guidance for each major provision
• Section 6037 reporting infrastructure is used to furnish built-in gain deduction amounts to shareholders
• Section 1447 withholding tax requires S corporations to remit tax and issue credits to nonresident alien shareholders
• Staggered effective dates: enactment date (built-in gain at death), December 31, 2024 (nonresident alien/IRA eligibility, withholding, deferred compensation), December 31, 2025 (suspended losses, passive income rules)
• Election procedures for electing S corporation status under Section 1369 to be prescribed by the Secretary

Legal References

• IRC § 6037
• IRC § 1447(f)
• IRC § 1446(f)
• IRC § 33
• IRC § 1369

Impact

The bill's most direct beneficiaries are S corporation shareholders engaged in estate planning, closely held business owners seeking greater flexibility in ownership structure, and S corporations with significant passive investment income. The transfer of suspended losses at death eliminates a longstanding tax trap for heirs of S corporation shareholders who previously lost the benefit of accumulated suspended losses when a shareholder died. The 15-year amortization deduction for built-in gains at death provides a meaningful tax benefit to heirs who inherit S corporation stock with a stepped-up basis, reducing the effective double-tax burden that can arise when appreciated S corporation assets are sold after a shareholder's death. The expansion of eligible shareholders to include IRAs opens S corporation ownership to a significant new class of tax-exempt investors, potentially increasing capital availability for S corporations and creating new estate and retirement planning opportunities. The inclusion of nonresident alien individuals as eligible shareholders removes a significant barrier to foreign participation in S corporations, though this benefit is partially offset by the new withholding tax regime under Section 1447, which ensures that nonresident alien shareholders' effectively connected income is subject to U.S. tax at the highest individual rate. The increase in the passive investment income threshold from 25 percent to 60 percent and the repeal of the termination-event rule substantially reduce compliance risk for S corporations with significant investment portfolios or those that have converted from C corporation status with accumulated earnings and profits. These changes are particularly beneficial for financial services businesses, holding companies, and S corporations that have historically been at risk of inadvertent termination due to passive income levels. The administrative burden on S corporations increases modestly due to new withholding obligations for nonresident alien shareholders and expanded Section 6037 reporting requirements. However, the repeal of the passive income termination rule reduces the monitoring burden that S corporations previously faced in tracking passive income ratios. The overall revenue impact of the bill is negative from a federal tax perspective, as the new deductions, expanded eligibility, and liberalized passive income rules collectively reduce federal tax receipts, though the new withholding tax on nonresident alien shareholders partially offsets this effect.

Legal References

• IRC § 1366(d)(2)(B)
• IRC § 1014(a)
• IRC § 1369
• IRC § 1375
• IRC § 1362(d)(3)
• IRC § 1447
• IRC § 408(a)
• IRC § 408A

Legal Framework

The bill operates entirely within Congress's Article I taxing power and amends the Internal Revenue Code of 1986, which is codified at Title 26 of the United States Code. The statutory authorities invoked span the core S corporation subchapter (Subchapter S, IRC §§ 1361–1379), the withholding tax provisions of Subchapter A (IRC §§ 1441–1446), the basis rules of Subchapter O (IRC § 1014), and the deferred compensation provisions of IRC § 457A. The bill does not implicate constitutional concerns regarding the taxing power itself, as all provisions are squarely within established congressional authority to define income, deductions, and withholding obligations. The regulatory framework is substantially delegated to the Secretary of the Treasury, who is granted authority to prescribe regulations and guidance under each major provision. This delegation is consistent with the broad regulatory authority Congress has historically granted the Treasury Department in the tax context, and the provisions are sufficiently specific to satisfy the nondelegation doctrine as applied in the tax area. The withholding tax under Section 1447 is modeled on the existing partnership withholding regime under Section 1446, providing a well-established legal template for the new rules. The bill does not preempt state or local law, as it operates exclusively within the federal income tax system. States that conform to the federal Internal Revenue Code may automatically adopt some or all of these changes depending on their conformity date and specific conformity provisions, but this is a matter of state legislative choice rather than federal preemption. The bill creates no express judicial review provisions, meaning that disputes arising under the new provisions would be resolved through the standard Tax Court, district court, and Court of Federal Claims framework applicable to federal tax controversies.

Legal References

• U.S. Const. art. I, § 8 (Taxing and Spending Clause)
• Internal Revenue Code of 1986, Title 26 U.S.C.
• IRC §§ 1361–1379 (Subchapter S)
• IRC §§ 1441–1447 (Withholding Tax on Nonresident Aliens)
• IRC § 1014 (Basis of Property Acquired from Decedent)
• IRC § 457A (Nonqualified Deferred Compensation from Certain Tax Indifferent Parties)
• IRC § 6037 (Return of S Corporation)

Critical Issues

The most significant implementation challenge is the complexity of the new Section 1369 built-in gain death treatment. The provision requires valuations of S corporation property as of the date of death, distinctions between amortizable and non-amortizable property, and coordination with the existing built-in gains tax under Section 1374. The interaction between the new 15-year amortization deduction and the Section 1374 built-in gains tax — which already imposes a corporate-level tax on recognized built-in gains within a recognition period — creates potential for overlap, double-counting, or unintended tax benefits that will require careful regulatory guidance to resolve. The election mechanism for electing S corporation status under Section 1369 adds another layer of complexity, as shareholders and their estates must affirmatively elect into the regime within timeframes to be prescribed by the Secretary. The expansion of eligible shareholders to include IRAs raises significant concerns about prohibited transaction rules under IRC Section 4975 and the potential for self-dealing between IRA owners and S corporations in which their IRAs hold stock. The bill references Section 4975(d)(16) in the context of conforming amendments, but the interaction between IRA investment in S corporations and the prohibited transaction framework is a known area of complexity that may generate litigation and require additional regulatory clarification. The withholding tax under Section 1447 creates new compliance obligations for S corporations that may not have previously tracked the residency status of their shareholders or maintained withholding infrastructure. The determination of effectively connected taxable income at the S corporation level, and its allocation to nonresident alien shareholders, requires coordination with existing international tax rules and may be particularly burdensome for smaller S corporations with limited administrative capacity. The cross-reference to Section 1446(f) for disposition withholding rules imports a complex and frequently litigated set of rules into the S corporation context. The repeal of the passive income termination rule under Section 1362(d)(3), while broadly beneficial to S corporations, eliminates a structural safeguard that prevented S corporations with accumulated C corporation earnings and profits from becoming de facto investment vehicles. Critics may argue that this change, combined with the IRA eligibility expansion, could be used to shelter passive investment income from tax in ways inconsistent with the original purpose of the S corporation regime. The staggered effective dates also create a transitional period during which different rules apply to different provisions, increasing the risk of taxpayer error and the need for careful professional guidance.

Key Points

• Coordination between new §1369 built-in gain deduction and existing §1374 built-in gains tax requires urgent regulatory guidance
• IRA shareholder eligibility creates prohibited transaction risks under §4975 that are not fully addressed in the bill
• §1447 withholding compliance burden is significant for small S corporations without existing international tax infrastructure
• Importation of §1446(f) disposition withholding rules into the S corporation context introduces a complex and litigated framework
• Repeal of §1362(d)(3) passive income termination rule may enable use of S corporations as passive investment vehicles
• Staggered effective dates increase transitional compliance complexity for practitioners and taxpayers
• Valuation requirements at date of death under §1369 will generate disputes over property characterization and fair market value determinations

Legal References

• IRC § 1374
• IRC § 1369
• IRC § 4975
• IRC § 4975(d)(16)
• IRC § 1362(d)(3)
• IRC § 1446(f)
• IRC § 1447