This release incorporates several revisions, structural changes, and enhancements. Major changes are described in the "Release Highlights" section of the publication. These and other changes, such as code changes, are also described in the online Financial Accounts Guide (www.federalreserve.gov/apps/fof/). The file structure of the Z.1 release consists of a single Z.1 PDF, corresponding HTML tables, and a single set of compressed CSV files with accompanying data dictionary text files. Data are available for download through the Federal Reserve Data Download Program (DDP). Series that appear in published tables are available immediately. Underlying detail series are generally available for download within two business days of the Z.1 release. The next Z.1 release will be Thursday, September 20, 2018, at 12:00 noon.