As long as you have testamentary capacity (i.e. you’re mentally competent), you can make changes to your will. You can change it a little, change it a lot, or completely revoke it, any time you want.
However, it is imperative that you work with a qualified estate planning attorney so that your changes are legally valid and well understood by your executor, the courts, and your beneficiaries.
In the “olden days” (i.e. pre-computers), small changes would be made via a “codicil.” A codicil is a small change, an amendment. Wills used to be a zillion pages long and hand written or type written. To avoid re-writing or re-typing the entire will, a codicil was drafted.
Multiple codicils could be confusing or even misplaced and, thus, were ineffective.
Now, in the computer age, codicils are rarely used. The entire will is redrafted on the computer, easily reprinted, and re-executed.
Both a codicil and a new will must be legally executed in order to be legally valid. If your will is not executed legally, it has no value and is as if you have not made any change.
Typically, your will must be signed by you at the end of the document, witnessed by two adult witnesses, and notarized.
To best ensure that your will works, meaning that it does what you want it to do:
Never make any handwritten comments on the documents.
Make updates every three to five years or sooner if your spouse dies, you get married or divorced, your executor becomes disabled or dies, you move to a new state, or you have a new child in your life.
Always work with a qualified estate planning attorney; there is a class action lawsuit in California now pending wherein a will downloaded from LegalZoom wasn’t properly executed; and, therefore, it wasn’t legally valid.
If you’d like to make changes to your will, you have the power to do so. Consult with a qualified estate planning attorney to best ensure that your changes are effective.