Two services, one scale
PCGS stands for Professional Coin Grading Service and NGC for Numismatic Guaranty Company. Both are independent. Each one examines a coin, decides whether it is genuine, grades its condition and seals it in a holder. Grades run on a 70-point scale.
Mint State and Proof
Coins struck for everyday release are graded Mint State, shown as MS. Coins struck with a special finish are graded Proof, shown as PF. The number after the letters is the grade, so MS70 and PF70 describe a coin in flawless condition.
Reading the number
A 70 is the top grade. A 69 is very nearly as good, with only the faintest flaws. A 68 is a fine coin with slight marks you can see under magnification. The gaps are small and hard to spot by eye, which is why an independent opinion is useful.
What a grade leaves out
A grade records condition on the day it was given. It does not set a price, and it does not mean a coin will rise in value or be easy to sell. The holder is tamper-proof, and you can check its certificate number with the grading service.
