Originally Posted by Thekipkers
After our last trip (4th do far) I removed the anode rod to flush the HW tank out. I noticed the anode rod is almost worn through close to the threaded plug and will need to be replaced soon.
That's how the anode rods normally wear, starting at the end nearest the threads.
There is a chart taken from Suburbans service manual at the following link that will show you when you need to replace the rod, which is normally around 75% of the rod dissolving.
As Youroo stated, you are still good to go for awhile.