For starters, there are two different time frames that are a part of this question: one for when you need to report an injury and one for when you need to file a lawsuit.
Reporting Injuries
The law requires that you report injuries to your employer as soon as is practicable after your accident. This is because you are required to give your employer reasonable notice of the accident and the claim. If you do not report it, or if you wait too long to report it, the insurance company will question whether the accident really occurred and can potentially deny your claim. It is always better to report the injury sooner than later.
Filing a claim
You have two years under Nebraska law from the date you knew or should have known about your work-related injuries to report them or two years from the last date the employer or insurance company made a payment to you or a medical provider. For most injuries, this date is the date of the incident or accident; however, the date can be a little more difficult to determine when it is a case of occupational disease or cumulative injury.
Talk to a lawyer as soon as possible to determine when you should file a claim.