The statute of limitations on hospital bills varies between states but is generally three to six years. It applies to payments due, not the billing itself. Hospitals can therefore continue to try and collect payment outside the limited time.
Medical bills are usually contracts with a definite time limit for payment. Unless agreed separately, hospital bills are due when services are given or within 30 days of billing. Bills rarely come as one complete payment request. Instead, the consumer receives separate ones for physician fees, hospital services, technician and equipment fees.
Misconceptions about insurance can result in non-payment of bills and the statute is no defense in these cases. Insurance companies are not responsible for paying the hospital on time, nor are hospitals responsible for billing them. The consumer is responsible for ensuring the hospital sends the bills and the insurance company pays them.
Statutes of limitations can be reinstated if you pay something after a period without payments;, the time limits begin anew. Similarly, the period covered by the statute of limitations can be paused (called "tolling") for reasons such as leaving the state. The clock restarts on your return to the state.