Methodology

Methodology controls for this guide

  • Official sources are listed with the date checked and what each source supports.
  • Federal scope, state/local exclusions, and assumptions are shown before any reader relies on an estimate.
  • Pages marked source-checked are not treated as expert-reviewed unless an external professional is named.
  • Material corrections update the page, date, and changelog instead of silently changing tax claims.

Key takeaways

What to know first

  • Capital gain or loss starts with sale proceeds minus adjusted basis.
  • Short-term and long-term classification depends on holding period rules and acquisition date.
  • Prior wage income, option exercise records, ESPP records, and broker basis must be reconciled.

Table of contents

  1. Why stock compensation basis is different
  2. Holding period basics
  3. What to check before filing
  4. Calculator link

Why stock compensation basis is different

Stock compensation shares often have a prior tax event before sale. RSU vesting, NSO exercise, ISO exercise, ESPP purchase, or restricted property transfer can affect basis and holding period records.

A brokerage Form 1099-B may not tell the full compensation history. The taxpayer may need employer records, grant documents, payroll records, and official forms to verify adjusted basis.

Holding period basics

IRS Topic No. 409 generally classifies gains and losses as long-term if the asset is held for more than one year and short-term if held one year or less.

IRS Publication 550 notes that property acquired through option exercise generally starts its holding period the day after exercise. Exceptions and special cases should be verified.

What to check before filing

Check sale proceeds, fees, cost basis, acquisition date, sale date, prior wage income, and whether any basis adjustment is needed.

For ESPP and ISO shares, also check whether the sale changes statutory option treatment or creates ordinary income that is not obvious from broker records alone.

FAQ

Is the amount on Form 1099-B always the right taxable gain?

Not always. Stock compensation shares may require basis adjustments or additional ordinary income review. Reconcile broker and employer records.

When does the holding period start?

It depends on how the shares were acquired. For property acquired through option exercise, Publication 550 generally points to the day after exercise, but special facts should be verified.

Does this guide include NIIT or state tax?

No. This guide is federal-focused and does not calculate NIIT, state tax, local tax, wash sales, or tax-loss harvesting rules.

Official sources

These links are used to verify the source family behind the page. They do not replace professional advice for personal facts.