Anyone involved in an accident and sustained an injury has a set amount of time before which they must commence action against the responsible third party.
As an example, if you were run over on say January 25th 2007 at which time you did not consider your injuries sufficient to warrant submitting a claim against the person that caused the accident but it now turns out that these injuries have now started to cause other problems, you have until January 24th 2010 to commence action through the Motor Insurers Bureau.
Whether pursuing a claim against someone who was insured at the time or not, you would be well advised to seek professional help and advice and appoint a legal representative to pursue the matter on your behalf as such matters can often become complex and technical.
Be in no doubt, there will be a few hoops you will be asked to jump through and a few hurdles to overcome that could manifest themselves due to the time lapsed since the accident requiring professional intervention probably.
Even if you don’t feel injured at the time, or there is nothing hurting, get yourself checked by your GP at the very least as soon after any accident as you can. This will assist any future claim by formally recording any potential medical problem.