How often should you replace a water shut-off valve?

How often should you replace a water shut off valve depends on type, water quality, and condition, but generally you do not replace on fixed schedule, you replace when it shows signs of failure or as preventative measure every 10 to 20 years for older gate valves, and longer for modern ball valves. Traditional gate valves with round wheel handle commonly found in older homes often fail after 10 to 20 years due to corrosion, mineral buildup, and seizing, so many plumbers recommend proactively replacing gate valves older than 15 years with quarter turn ball valves, which last longer, typically 15 to 25 years or more, and provide more reliable shutoff. Ball valves can last 20 to 30 years with minimal maintenance if not abused. You should test shutoff valves annually by turning them off and on to ensure they operate and fully stop flow, a process called exercising, which helps prevent seizing and extends life. Replace valve if it leaks at stem, does not fully shut off water, handle is broken or very hard to turn, or shows visible corrosion. For main shutoff, proactive replacement before emergency is wise. For fixture angle stops under sinks and toilets, replace when you remodel or if they are original and hard to turn, as failure during leak can cause water damage.