Each year NCCS publishes three Core files (yyyy = circa year represented in each file):
1. Core yyyy PC = 501(c)(3) public charities
2. Core yyyy PF = 501(c)(3) private foundations
3. Core yyyy 501(c) others = 501(c) organizations other than 501(c)(3) public charities and private foundations
The raw data is posted as a ‘Beta’ version as soon as it becomes available from the IRS, then the Beta version is replaced by the Final version once the data is verified (see link below for more on the verification process).
Verification is designed to correct most significant problems in financial data before the file posted as “Final version,” but errors in individual records may be corrected in final versions of Core files as needed.
The data in each Core file represents a circa year (versus a single tax year like SOI, or a single Fiscal Year). Core files begin with data processed by the IRS in the most recent calendar year, then are back-filled with data processed in the prior year. For example, the bulk of Core 2007 data represents all return data processed by the IRS between Jan 2007 through Dec 2007, but a small number of records may have been processed in the prior year.
The time lag from when an organization’s fiscal year ends to when the IRS processes the return for that fiscal year is normally at least 1 year, but is often as much as 3-5+ years for any number of reasons. During any given year the IRS will process returns for tax periods ending 6 months ago to 10+ years ago. For this reason NCCS has found that it takes at least 3 years or more for enough return data to become available to adequately represent a specific tax year or fiscal year. To overcome this lag the Core files are based on circa year periods.
The range of the circa year period is limited to fiscal periods starting in the most recent calendar year, plus the prior two calendar years. For example, the first round of records selected for Core 2007 will be limited to fiscal years starting in 2007, then we add returns starting in 2006 for any missing organizations, then add missing returns starting in 2005 for any remaining. In other words, Core 2007 will contain returns for tax years beginning Jan 1, 2005 through December 31, 2007 (styear = 2005, 2006, or 2007).