It's crucial to check your owner's manual. This manual will provide the specific recommended replacement interval for your particular Sebring's engine (it likely has either a 2.4L or a 2.7L engine). Ignoring the recommended interval can lead to catastrophic engine damage. If you don't have the manual, you can often find a digital version online through the Chrysler website or a reputable parts retailer.
Even if the mileage hasn't reached the recommended interval, it's also advisable to have the timing belt inspected by a mechanic every 60,000 miles or so. This inspection can identify potential problems before they lead to a failure.