What type of tenancy should we choose?

Your wife has a legally protect-able interest, not you. She is the one that needs legal advice, not you.

"An ounce of prevention is worth a pound of cure". Obtain the assistance of a probate lawyer who can properly advise you as to the type of tenancy title you and your wife should agree on in light of your circumstances, because any tenancy title you choose may a long term effect the surviving person will come to regret. This is not the time to be frugal with the dollar.

California uses just the first two types of property ownership. If she is going to gift you a 50% interest in the property, there may be tax consequences; upon her death there will be no stepped up basis. A joint tenancy avoids probate and can easily be converted into a tenancy in common. Read some Nolo Press books on real estate before making such a decision to give up half of her interest in the property.

Why have you not considered husband and wife as community property or husband and wife as community property with right of survivorship? Joint tenancy is probably a bad idea, but it depends on what you want. Tenancy by the entirety does not exist in California and should NOT be used.

If your wife intends to hold the property with you as community property and you do not have a revocable trust, then community property with rights of survivorship would likely be your most advantageous option.

There is a lot more information which is required to analyze the situation. There are basic questions that need to be answered... like why does your wife want to put your name on the deed? Does she intend on making a gift of a 1/2 interest in the property to you? Does she intend on giving you 1/2 of the equity in the property if you were to divorce? Is she looking for a means of transferring the property to you when she dies? If you divorce before she dies, then does she intend on giving you 1/2 the equity then? Do you have children together? Does she intend to have her children inherit her property? If your wife intends on allowing you to have the income from the property if she dies first, and she does want the property to go to her children after your death, is she willing to take a chance on your giving the property to your new girlfriend and her children never getting the benefit of her ownership? There are income tax laws, property tax laws, probate laws, gifting laws, and family law issues surrounding the transfer of property. Your wife should retain an attorney to discuss all these issues before making a decision on a transfer of an interest in property that is in her name and would like be her separate property. Should you have any questions or wish to discuss this matter further, please feel free to contact me.