The simple answer is no. Trusts by themselves do not avoid probate, but they make probate avoidance possible. Think of the trust agreement as a box. Anything put in the box does not require court administration (probate) to pass to the beneficiaries. This is known as funding the trust and is one of the most common reasons good estate plans fail.
Failure to fund can happen in a variety of situations. Perhaps funding was never completed after the documents were prepared, perhaps new assets were acquired but not titled in the name of the trust, or perhaps assets were forgotten such as old investment accounts or out of state property. Regardless, any of these circumstances could result in an otherwise unnecessary probate administration.
For these reasons, it’s a good idea to periodically review your assets and ensure you know how they are titled and how they would pass on your death. Your attorney or financial adviser can assist in this review.