>Note that things get a bit more complicated if the spouses get divorced by the time of the sale of the stock subject to the 83(b) election. Because both spouses (are deemed to have) paid taxes on the 83(b) stock due to the 83(b) election, absent a prenup or postnup generally the 83(b) stock is treated as marital property and the proceeds are similarly marital property
Paying or not paying tax has no bearing on what is considered community property. It's also not clear what is "more complicated" about splitting marital property subject to an 83(b) election compared to other marital property.
Paying or not paying tax has no bearing on what is considered community property
Yes, it does. In the event of divorce, in the absence of a prenup or postnup explicitly stating that the [83(b) stock or other income] is one spouse's separate income, the payment of taxes on a joint return is the single most important evidence of whether income is considered marital income or separate income, the legal reasoning being that a spouse would not have paid taxes on the other spouse's separate income.
It's also not clear what is "more complicated" about splitting marital property subject to an 83(b) election compared to other marital property.
The "more complicated" is in comparison to how 83(b) elections are treated if the spouses remain together. It's not a comparison to other marital property, though in general stock in a company that is not yet publicly traded can be extremely complicated to divvy up in a divorce.
> the payment of taxes on a joint return is the single most important evidence of whether income is considered marital income or separate income,
I would expect that in the absence of prenup/postnup, the laws of the community property jurisdiction would take effect, making all earned income community income. Which law or regulation, for example in California, states that federal tax must be paid on income via a joint tax return for it to be treated as community income?
What if in the same year as the 83(b) election, the MFJ return shows no tax liability, due to credits, little other income, large deductions, etc. Does that suddenly make community property law moot?
Paying or not paying tax has no bearing on what is considered community property. It's also not clear what is "more complicated" about splitting marital property subject to an 83(b) election compared to other marital property.