Do I pay capital gains tax in 2019 or 2020 for stock sold in 2019 at a profit after holding stock for over a year?

[Hal_Al · Accepted solution]

You pay the tax (if any) in 2020, when you file your 2019 tax return.

At, your option, you may make an advance  "estimated payment" in 2019, but you are not required to. 

Long term capital gains are subject to special (reduced) tax rates and can be 0% on some of the gain.

[Anonymous]

if the gain was substantial you may need to pay estimated taxes to avoid underpayment penalties.  try tax caster

[Hal_Al]

The "Taxcaster" tool is here:  <a rel="nofollow" target="_blank" href="https://turbotax.intuit.com/tax-tools/calculators/taxcaster/?s=1">https://turbotax.intuit.com/tax-to...>

Underpayment penalty is due  if both of the following apply:
- 1. You  to owe at least $1,000 at tax time, after subtracting your withholding and credits.
- 2. Your withholding and credits was less than the smaller of: 90% of the tax to be shown on your current year’s tax return, or  100% of the tax shown on your prior year’s tax return.

The underpayment penalty is currently about 5.5% interest rate

[Critter]

2019 ... it is reported in the year it was sold.