This chapter examines the process by which modern lexicographers enter words into their dictionaries. Before we can discuss how a word gets into an English dictionary, we must first understand the purpose of the modern English dictionary and contrast that purpose with the purpose of historical English dictionaries. A general understanding of early English dictionaries, including the audiences they were written for, establishes the historical methods early lexicographers used when entering words into their dictionaries. We then examine the techniques Samuel Johnson used in writing his 1755 A Dictionary of the English Language, as these methods become the basis for the modern English dictionary. There is then an in-depth discussion of the criteria lexicographers use when choosing words for entry, as well as an overview of the process itself and how the Internet has affected these centuries-old methods.