I will have have no earned income in 2021 and my spouse will make 20k gross for 2021. So, in other words we will have 20k gross income and we file jointly.
Q- if we have long term capital gains from selling stock in 2021 do we have to pay capital gains tax based on above info?
Basically, the long term cap gains rate is zero as long as your regular tax rate is at the 12% or 10% level, but once you hit the 22% tax bracket, your long term capital gains are taxed at 15%. For married filing jointly, the 22% bracket starts at $85,051. Then you add the standard deduction of $25,100.
So if your total income is less than $110,151, the part of that income that is LTCG would be tax-free. If your total income is more than that, you will start to pay tax on your LTCG.