IF you have "meaningful" assets in any kind of Retirement Account (e.g. IRA, 401-k etc.)
AND
IF you have specific wishes about where these assets go after your death
Please be prepared for some details that might be new and important to you ...
NB. Consult your attorney about your specific facts including the laws of your state of residence.
Asset Location
JTWROS - Joint Tenancy with Right of Survivorship
If you have account(s) "owned" as JTWROS, then the assets in that account will (typically) go to the last-to-die of you and your joint owner.
If you have account(s) owned by a trust, then those assets will typically be distributed according to the trust document..
Beneficiary Designation Forms can be critically important
This information is not intended to be a substitute for individualized legal advice. Please consult your legal advisor regarding your specific situation.