Welcome to the 2023 US Error Coin - Color Edition. No other error guide presents over 3,500 error coin listings with more than 20,000 graded values. This book is a complete listing of all types of error coins created in the minting process. Error coins are classified into three categories, die errors, minting errors, and planchet errors. Die errors occur when a die is created by misaligning the steel rod used to create a die into the hub. Before 1996, mint workers added the mintmark to a pre-made die-the misstriking of a punch used to create a mintmark created RPMs. In addition, if a mintmark was removed and replaced, sometimes traces of the first mintmark remained on the die, causing an RPM. Mint dies were often exchanged between die locations where a mintmark from one mint site was replaced with another, often resulting in over-mintmarks (OMM). Planchet errors are created in the blanking process resulting in partial planchets. Planchets can also be defective, splitting before or after the strike. Some of the rarest planchet errors result from using the wrong metal or transitional metals. This guide presents all of the error types with photos and descriptions. The most extensive glossary of numismatic terms is provided for collectors' use as a reference. Each term has been validated by extensive research with numismatic organizations. A modern-day error coin list of RPMs, DDO, and DDR coins shows the error for reference. The values in this guide are a compilation of attending hundreds of auctions over ten years to record final auction prices to provide collectors with information to buy and sell error coins with confidence. There is no other guide that contains this information. The changes are noted by the "year" entered at the end of the error listing every year.