QSBSCalc
Sources

Citation
manifest.

Every numerical claim, every statutory rule, every regulatory cross-reference on the site traces back to one of the primary sources listed below. The supplementary references at the bottom are never load-bearing.

Last updated: May 11, 2026

Primary sources

The load-bearing citations

Every numerical claim, every statutory rule, every regulatory cross-reference on the site traces back to one of these.

IRC §1202statute

Partial exclusion for gain from certain small business stock.

verified 2026-05-11open ↗
IRC §1045statute

Rollover of gain from qualified small business stock to another QSBS.

verified 2026-05-11open ↗
IRC §1244statute

Ordinary-loss treatment for losses on §1244 small-business-stock.

verified 2026-05-11open ↗
Treas. Reg. §1.1202-2regulation

Qualified small business stock; effect of redemptions. De-minimis test: aggregate redemptions >$10,000 AND >2% of taxpayer-held stock disqualify QSBS status. Death/disability/divorce exceptions apply.

verified 2026-05-11open ↗
Treas. Reg. §1.1045-1regulation

Application to partnerships.

verified 2026-05-11open ↗
P.L. 119-21 (OBBBA)legislation

One Big Beautiful Bill Act, signed 2025-07-04. Section 70431 of P.L. 119-21 modifies §1202 with the new tiered exclusion (50% at 3 years / 75% at 4 years / 100% at 5+ years), the raised per-issuer cap ($10M → $15M), and the raised aggregate gross-asset ceiling ($50M → $75M) for stock issued/acquired after 2025-07-04. Pre-2025-07-04 stock retains the legacy 5-year/100%/$10M/$50M regime. Inflation indexing begins TY2027. Internal subsection labels — (a)(1)-(3) for the tiered exclusion, (a)(4)(B) for the cap, (a)(5) for the ceiling — are inferred from Cornell LII's amendment footnote on 26 U.S.C. §1202; primary-source confirmation against the P.L. 119-21 bill text is pending.

verified 2026-05-11open ↗
Treasury/IRS guidance on OBBBA §1202 (pending)fed-register

Federal Register implementation notice not yet published as of 2026-05-11; placeholder slot for tracking. No Treasury Notice, Rev. Proc., or Federal Register publication interpreting OBBBA §70431 / IRC §1202 has been located. Update url + note when first guidance drops.

verified 2026-05-11no published URL yet
IRS Form 8949 instructionsirs-form

Sales and Other Dispositions of Capital Assets. §1202 exclusion reported with adjustment code Q.

verified 2026-05-11open ↗
IRS Pub 550irs-pub

Investment Income and Expenses — capital-gains framework, QSBS treatment.

verified 2026-05-11open ↗
State DOR portals
State DOR + state-legislature primary sources

50 states + DC

Each state-conformity claim on /states links to the state's own Department of Revenue portal or legislative-statute source.

Supplementary
Supplementary references

Secondary — informational only

These secondary references inform our editorial framing of OBBBA's §1202 changes but are never load-bearing as citations. Every claim on the site that paraphrases one of these is independently verified against a primary source first. Listed here for transparency and so readers can cross-check.