Employee equity is one of the most powerful retention and alignment tools in private companies and one of the most poorly explained. Done right, it makes employees part-owners. Done wrong, it produces angry tax surprises and litigation.
ISOs vs. NSOs
Incentive Stock Options (ISOs): tax-favoured, US-only, with strict eligibility rules (employees only, $100K vesting cap per year, 10-year expiry, 90-day post-termination exercise). Properly held, ISO gains are long-term capital gains. Non-qualified Stock Options (NSOs): ordinary-income tax at exercise on the spread between strike and FMV. Anyone can receive NSOs (including contractors and advisors). For most US employees, ISOs up to the $100K cap are preferable; the rest of the grant is NSO.
The 83(b) election
When restricted stock vests, the holder owes ordinary income tax on the spread between strike and FMV at vesting. For early-stage founders this can be small at grant and very large at vesting. The 83(b) election, filed within 30 days of grant, accelerates the tax to the grant date — paid on a tiny spread, locking in long-term capital-gains treatment for any subsequent appreciation. Missing this 30-day window is the most common preventable tax mistake in early-stage founders' lives.
Vesting schedules
Modern default: 4-year vest with 1-year cliff — no shares vest in the first year, then 1/4 vests at month 12 and the rest monthly over the remaining 3 years. The cliff protects against early-quitter dilution. Acceleration can be single-trigger (full or partial vest on a sale) or double-trigger (vest on a sale and termination by the buyer). Double-trigger is the modern default for senior employees; single-trigger is sometimes negotiated by C-level.
409A valuations and strike pricing
A 409A valuation is an IRS-blessed independent valuation of the company's common stock, used to set the strike price on options. Without a 409A valuation, options can be deemed under-priced and trigger a 20% federal penalty on the holder. Modern startups refresh 409As annually, after major financings, and at material business changes. Strike-price discipline keeps the option program compliant and the resulting taxation clean.
QSBS — Section 1202 and the founder/early-employee tax shield
Qualified Small Business Stock (QSBS) under IRC §1202 allows a non-corporate taxpayer to exclude from federal income tax up to 100% of the gain on the sale of qualifying stock — up to $10 million or 10 times the taxpayer's adjusted basis in the stock, whichever is greater. The exclusion applies to stock acquired after September 27, 2010 and held for more than five years. For a founder who bought shares at a nominal price and held through a meaningful exit, this provision can shield tens of millions of dollars of capital-gains income at the federal level. Note: state tax treatment varies — California, for instance, does not conform to the federal QSBS exclusion. This is general information, not tax advice; consult a qualified tax advisor for your specific situation.
To qualify, the stock must have been issued by a domestic C-corporation whose aggregate gross assets did not exceed $50 million at the time of issuance (and immediately after). The company must be engaged in an active qualified trade or business — certain professional services (health, law, finance), hospitality, and farming businesses are excluded. These requirements mean QSBS is most commonly applicable to venture-backed technology, life sciences, and software companies. When a financing round is planned, founders and early employees should confirm the company's gross-asset position relative to the $50M cap before the round closes; a round that pushes gross assets over the cap does not retroactively disqualify prior stock, but new shares issued post-cap are ineligible.
Practical execution requires attention to three administrative steps. First, track the exact issuance date of each tranche of stock — the five-year holding clock starts at issuance, and partial dispositions that trigger the clock on a later-issued tranche are a common pitfall. Second, file the 83(b) election within 30 days of grant on any restricted stock; this establishes the grant date as the holding-period start and locks in the basis for the exclusion calculation. Third, keep clean cap-table records with documentation of the company's gross assets at each issuance date — this is the IRS audit trail. Secondary sales of QSBS before the five-year mark do not qualify for the exclusion, and acquisitions can be structured to preserve or terminate QSBS status depending on how consideration is paid; both scenarios require tax counsel review before execution.