“Piggybacking credit” is a new practice that helps consumers improve their credit scores by paying to become “authorized users” on established accounts. Authorized users are not liable for paying an account, but because of Regulation B (which implements the 1974 Equal Credit Opportunity Act), the account's history factors into their credit scores. As a result piggybacking can be used to manipulate the signal of creditworthiness that scores provide and may help borrowers obtain credit for which they would not have otherwise qualified. This article investigates the policy questions raised by piggybacking. First, we evaluate whether the credit history disparities that motivated these provisions of Regulation B have persisted since they were written. Then, we assess the potential for score improvement through piggybacking. Finally, we evaluate the likely score effects of allowing credit scoring models to exclude authorized-user accounts, the most widely proposed policy response to the emergence of piggybacking.