The above posts are not 100% correct. While some TPGs will not grade counterfeit coins, they will grade counterfeits that have historical perspective. For example Moonlight mint coins/tokens are graded and they aren't legal tender.
Several TPG's will grade california gold rush tokens, which were created long after they were outlawed by the US Government.
Even modern day historical counterfeits can be graded. For example the below is mine.


What TPG's will generally not grade are counterfeits designed to fool a buyer (for example a fake Mercury dime 16D).
Whether a counterfeit is graded really depends on its historical significance or if its market acceptable.
Several TPG's will grade california gold rush tokens, which were created long after they were outlawed by the US Government.
Even modern day historical counterfeits can be graded. For example the below is mine.


What TPG's will generally not grade are counterfeits designed to fool a buyer (for example a fake Mercury dime 16D).
Whether a counterfeit is graded really depends on its historical significance or if its market acceptable.



















