Normally you have 2 years from the date of last payment made on behalf of the injury.
Meaning any of your TTD, TPD, PPD, PTD payments made to you, then 2 years from the date of those checks....or ANY medical bills, prescriptions, etc... Whenever the last payment was, you would have 2 years from that date. Every state is different and I would seek consultation quickly!
Most Work Comp attornies offer a FREE first time initial consultation....so get one scheduled quickly! If you don't like what they have to say, then shop around for 2nd and 3rd opinions....If they all say the same, then you can decide form there on who/where to go with this. I would act quickly though! Good luck!
