There is a very serious time limit, which varies from state to state. In Massachusetts, you have three years from the date you knew or reasonably should have known that some error or omission by your attorney caused you some appreciable harm, even if you are not yet sure what the nature or extent of the harm may be. If you do not file your malpractice suit in court by that date, you are forever barred from doing so. The statute of limitations for suing an attorney for malpractice may differ in your state. You should never, ever, do your own calculations of when your statute if limitations period begins or ends. Only after a thorough review by a competent lawyer can this question be answered with any degree of certainty. The safe way to handle this is to consult with a competent attorney as soon as you can after you first learn that something has gone wrong with your case that you suspect is the fault of your attorney.