The tax-exempt sector under section 501(c) of the IRS Code covers over a million-&-a-half tax-exempt entities (TEE) of varying sizes & purposes. Transparency over TEE activities is aided by public access to their annual tax returns. Oversight can help ensure adherence to exempt purposes, protect against abuses, & sustain public support for the sector. This report addressed: (1) the growth of the section 501(c) tax-exempt sector; (2) the role of governance & transparency in ensuring that TEE function effectively & with integrity; (3) IRS's capacity for overseeing the TEE sector, incl. its results & efforts to address critical compliance problems; & (4) states' oversight & their relationship with IRS in overseeing TEE. Charts & tables.