Medi-Cal.

An Inheritance is not Community Property in California. Keep it separate in Mom's name, in a different bank.
Get a quick visit with a Medi-Cal lawyer, so no mistakes are made in the process.

I understand that an inheritance is not part of marital assets as long as kept in a separate acct under the beneficiaries name. Mom may need to fill out a Spousal form that says she will not be paying for Dads care. It may effect how much she gets though monthly.

Yes, you have to show all monthly income. Not sure if they can use Moms SS for Dads care because SS is only for the person who earned it. You really should see an Elder lawyer and have your parents assets split. Dads split will pay for Dads care and when gone Medicaid can be applied for. An Elder lawyer can explain further and help with the Medicaid application when the time comes.

Your mother's inheritance is HERS AND HERS ALONE until it is melded with your father's accounts. This is to say that if you put your mother's inheritance in a separate account it belongs only to her.
Now as to how it works in a community property FEDERALsystem with Medicaid? Anyone's guess here and maybe Igloo knows. I sure don't I hope she will respond. I suspect, if a couple is married, that the federal government considers marital assets to include all holdings.
Igloo, to me is our resident expert on answers to this sort of question. But even she says that this stuff is not DIY (do-it-yourself).
You cannot afford to be WRONG on this stuff.
Do yourself the favor of consulting an attorney.
I surely do wish you the best.

Speak to a Certified Elder Care attorney about this matter.