Answered on Aug 20th, 2012 at 1:59 PM
The Statute of Limitations depends on who you would be suing. Generally, for workers' compensation cases the Statute of Limitations is 2 years from either the date of your injury or the date of the last payment (only certain payments count) by the employer or the employer's workers' compensation insurer for a work-related injury.
If your case is against someone other than your employer, the Statute of Limitations may either be 2, 3 or 4 years depending on it is at fault. If the government, a governmental agency, a political subdivisions (such as a city) or any of their employees, you must file a Tort Claim before you can file suit.
The details about suing one of these is complicated and difficult to explain in this format. If the case is against a private citizen or company, the Statute of Limitations is generally four years from the date of your injury. You also ask, "Can I reopen the claim or sue for medical expenses?" This depends on both the Statute of Limitations and whether you entered into a full and final settlement.
If the Statute of Limitations has not expired and you did not sign a release or enter into a full and final settlement, you could still pursue a claim for medical expenses. I would suggest talking to an attorney about the Statute of Limitations and re-opening your case. Most offer a free consultation so it will not cost you anything to learn more about these items.