The IRS generally treats an 83(b) filed by <i>either spouse</i> as jointly filed by the union if they file a joint tax return. Whether they are in a community property state or not is irrelevant from the perspective of <i>federal</i> taxes because the <i>marital joint return</i> already deals with this situation: essentially, the union is treated as a single taxpayer.<p>(And yes, for those of you who are wondering: a federal tax statement/election signed by one spouse that files a joint return can bind both spouses for federal tax purposes...)<p>As written, neither 83(b) nor its regulations (specifically 1.83-2, which outlines the requirement for the election) require spousal consent to an 83(b) election, because they are not the person earning the income. The regulations specifically state that the statement is filed by the "person who performed the services." They then pay taxes pursuant to the 83(b) election with the joint tax return, meaning that <i>both</i> spouses have paid their federal tax liability with respect to any future sale.<p>If this were not the case, the spouses of hundreds of thousands of CA tech workers would owe tens of billions of dollars in back taxes. It would be front page news. But it's not, because it's not actually how federal taxation works...<p>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 to be divided in a divorce. In a community property state, the split is 50/50 (I assume the same is true in non-CP states but as I've never dealt with this outside of CA I can't say). However, note that it's still irrelevant as to whether the other spouse signed the 83(b) election, so long as the election was made while they spouses still filed a joint return.<p>TLDR: for <i>federal</i> tax purposes, not having a spouse sign your 83(b) election is a non-issue, whether or not you live in a community property state.