Does anyone know the in's and out's of savings bonds when the elder is a co-owner on the bond?

The co-owner is married, but the spouse is not the primary on the bond.  What happens in a community property state when the co-owner passes? The primary has all the cancelled checks to prove they actually purchased the bond... and the co-owner was put on the account in case the primary owner got hit by a bus.
Does the money become part of the resources if that senior applies for Medicaid?
Anyone know... Thanks.