Many have called for algorithmic accountability: laws governing decision-making by complex algorithms, or artificial intelligence (AI). The EU's General Data Protection Regulation (GDPR) now establishes exactly this. The recent debate over the right to explanation (a right to information about individual decisions made by algorithms) has obscured the significant algorithmic accountability regime established by the GDPR. The GDPR's provisions on algorithmic accountability, which include a right to explanation, have the potential to be broader, stronger, and deeper than the requirements of the preceding Data Protection Directive. This Article clarifies, including for a U.S. audience, what the GDPR requires.