Continuing with the theme of cross-border mobility and resulting tax consequences, U.S. tax law contains provisions that affect married couples coming to live in the U.S. from a country that has a community property regimes in force and effect. They may find that income tax consequences are not necessarily controlled by the marital laws of the former home country. The Internal Revenue Code contains provisions that apply to earned income that override community property regimes when one or both spouses are not U.S. residents or citizens. Nina Krauthamer and Galia Antebi address the circumstances controlled by Code §879. They also address rules for filing joint income tax returns when one spouse is not a U.S. citizen or resident, available elections under Code §6013(g) and (h) to allow for the filing of joint tax returns, elections for arriving persons to be treated as residents with an accelerated residency starting date, and tricky trust and estate rules that apply to a donor spouse when the donee spouse is not a citizen. A must read for arriving individuals.