When Special Care Is Needed: The Special Needs Trust A special needs trust helps care for a special needs child when you’re gone. Share | Have A Question About This Topic? Address Thank you! Oops! Related Contents When Do You Need a Will? When do you need a will? The answer is easy: Right Now. Put It in a Letter A letter of instruction provides additional and more personal information regarding your estate. Principles of Preserving Wealth How federal estate taxes work, plus estate management documents and tactics.