In Nevada, if you are seeking damages for personal neglect or negligence it is within two years. Assault and battery or another intentional act is also two years.
There may be exceptions so be sure to talk to an experienced elder abuse attorney as soon as possible. As on example, in Nevada, with the county hospital, it is two years, but you also have to make a tort claim under the Tort Claims Act and then they have a right to review it.
You could file a lawsuit at the same time you file a claim. If it is a federal hospital, you only get to file the claim, then they wait for a determination from the federal government on the tort claim.