Yes, you are still within time (at least 5 years in your state, based on the statute of limitations for contract cases, which ranges from 5-10 years based on the type of contract) to seek payment from this client. You could ask them to track and reissue IF the check has not been cashed (though you would have to pay them any stop payment or similar fee that would be appropriate to pay to protect them against the check "resurfacing" later), and if they won't, could potentially sue for the money.If the check has been cashed by someone, so that it is reasonable or likely that it was sent to you and then intercepted (e.g. taken out of your mail) or lost by you and found by another, you cannot get them to reissue it: they fulfilled their obligation by sending it out in the first place, and what happens later is not their responsibility. You could potentially sue the person who cashed their check for the money.