As with much in life there is no simple answer. It depends!
The general rule is that a suit against a lawyer should be brought within three years of:
When the lawyer screwed up or
The last time the lawyer was working on your case or
The last time the lawyer tried to fix the screw up or
The first time you spoke to another lawyer about the negligence of your lawyer.
If the law suit is not brought in time you loose all of your rights but there are always exceptions. One of which is if the lawyer fraudulently hid the screw up it is three years from when you figured it out or should have figured it out.
BUT don't rely on this and figure it out on your own. It really is much more complicated then what I have told you here. Don't try and analyze this your self. Sorry but if you have been damaged by a lawyer you still should have a lawyer you can trust help you. Can We Help You? I hope so. Call us if you think you have been damaged by the screw up (malpractice) of a lawyer.