Can I prevent my spouse from giving my money away to a new spouse if I pass away?

Yes, if you set up a revocable living trust and structure if with certain protections and restrictions.  For married couples owning joint assets, you can decide how to direct your half of the money when you pass away.  Sometimes, spouses choose to leave their share of the money to the surviving spouse, outright and without any restrictions.  This means that while the surviving spouse retains complete control and flexibility over the late spouse’s assets, the surviving spouse is also free to give the money away to a new spouse, or lose it to a creditor, predator, lawsuit, or divorce.  Spouses do have the option to safeguard their share of the money upon their death, so it can support the surviving spouse, but also prevent his or her from giving it away to anyone other than the secondary beneficiaries they had agreed on (usually the children), or losing it to an ill-intentioned third party.