In my will, can I refuse to provide for some members of my family?

Specifically excluding a person from inheriting part of your estate is called disinheriting. A married person cannot disinherit a spouse without the spouse’s consent or minor children which they have a duty to support. You may specifically exclude or disinherit an adult child, as long as you are clear about it in the will so the disinheritance does not appear to be a mistake.