Certified coins are any coins that have been graded and authenticated by a major grading service like NGC or PCGS. Investors may prefer certified coins as they are guaranteed to be authentic, are typically in outstanding visual and aesthetic shape, and often are worth much more than just the gold or silver contained in the coin.
When looking for and deciding between different certified coins, you will undoubtedly come across some coins graded by the NGC while others are graded by the PCGS. The first question that comes to mind is whether one grading service is better than the other, and the answer to that is no.
Both services grade coins on a 1-70 scale with 1 being the worst quality and 70 being the absolute best. While the adjectival initials accompanying each number grade may be different between the two grading scales, it does not make one grading service better than the other. At the end of the day it does not matter whether your coin is graded by the NGC or PCGS, all that really matters is the grade of the coin.
Every graded coin comes encased in a plastic slab that works to not only protect the coin but also to display the coin’s grade. At the top of every slab is a small insert that contains the name of the coin in the case and its grade, as well as a barcode and unique serial number. The barcode and serial number exist in order to allow the owner of the coin to verify its grade via the PCGS or NGC websites.
Tampering with or removing the coin from its protective plastic slab is not recommended as doing so will likely alter the grade of the coin, and thus its value.