Not all squirrel-proof bird feeders will be raccoon-proof, but most (if not all) raccoon-proof bird feeders will be squirrel-proof.  You also have a better chance if the feeder has weight-sensitive perches or ledges that shut off the feeding ports. The tricky part is when you have a pole or shepherd's hook supporting your feeder. The baffle you will need to put around the pole is smaller in diameter and length for squirrels than for raccoons simply because squirrels are smaller and shorter. The baffle will keep wildlife from crawling up the pole to the feeder. The other consideration is the lid or top of the feeder. Raccoons are very ingenious when it comes to getting lids off of anything. Check out this raccoon guard at Duncraft.