My main water shutoff valve is rusty. Does it need replacing, or is it okay?

Surface rust on an older main shutoff valve, especially in a damp area, is common. First, check closely for active leaks around the valve body or stem. If it's just surface rust with no drip, you can clean it with a wire brush and apply a rust-inhibiting paint to protect it. However, if the rust is severe, pitting the metal, or if the valve is actively leaking or won't turn, it's failing. Replacing a main shutoff valve requires shutting off water at the street, which needs a licensed plumber and often coordination with your water utility. This is not a DIY job due to the flood risk and specialized tools. A permit may be required.