When someone asks me to set up an estate legal program to avoid probate, they often ask me something like, "Do ALL of my assets need to be in my trust to avoid probate?"
It depends on what kinds of assets that you own, but most people do not need to transfer all of their assets to their trust. Some assets that you own, by their nature, avoid probate.
IRAs and other retirement accounts, avoid probate. When you die, your IRA is payable to your designated beneficiary, outside of probate. In fact, IRA rules do not allow you to transfer your IRA to a trust during your lifetime. This applies to both traditional and Roth IRAs - they avoid probate.
When avoiding probate is the primary goal, ownership of life insurance does not need to be transferred to your living trust. When you die as the insured, your life insurance death proceeds will be payable to the beneficiary that you designated.
Annuities are another example of an asset that avoids probate, just like life insurance.
Note that it might make sense to name a trust as the beneficiary of these non-probate assets, but check with your estate planning attorney to determine the appropriate way to designate beneficiaries on your non-probate assets.