Legal Question in Wills and Trusts in Florida

If the account is a standard bank savings account and you have designated only your sisters as POD( payable on death) beneficiaries, your husband will not participate in the distribution.

If a POD, TOD, ITF or ATF, then probably not. However, if he doesn't get at least 30% of your estate on your death (assuming no pre-nupt) then yes he can go after your assets to make up to that.

The legislature made sure you can't completely disinherit your spouse without their consent.

It is true that the elective share of your spouse must be honored, however if it is your choice to keep the same from his elective rights then there are other ways to set up the account to provide this, specifically gifting that occurs at least 1 year prior to your own death, and with the use of trusts, and other documents you could arrange the same with your sisters to avoid such elective right. The Banks have had a great influence in creating what is known as a "conclusive presumption" in bank accounts that are titled in multiple names such as you may have set up.