How long can I wait before I file a lawsuit?
That depends. Some actions require prompt initiation of a lawsuit, while other matters can be given more time. Statutes of limitation exist in both the federal and state law system. If you file a lawsuit beyond the applicable statute of limitation, the defendant can demur (that is, file a pleading that basically says, "So what? The plaintiff waited too long and now recovery is barred by law"). In addition to the defense of the applicable statute of limitation, a defendant may raise the "equitable argument of laches" (the plaintiff has been "sleeping" on his/her rights for so long that recovery should be barred).
There is generally a longer period of time for controversies relating to real property than there is for personal injury. Complaints regarding a written contract usually can be filed later than a complaint based upon an oral contract. Determining when the statute of limitation begins can be complex. Some limitations are based upon when a plaintiff should have known there was a problem. There are also rules regarding the tolling (suspension) of the statute of limitation (for example, the statute does not run while the defendant is out of state, is a minor, or is insane).
Just because there is a long period of time before a lawsuit must be filed does not mean that the period must be almost expired before filing. While other methods of dispute resolution can be used before filing, it is important not to allow a statute of limitation to expire, and thereby defeat any potential change for recovery. Remember the adage, "If you snooze, you lose." Determine the date of the applicable statute of limitation well in advance, and then don't get caught short.