S&P Global Ratings assigned its 'AAA' long-term rating and 'AA-' underlying rating to East Central Independent School District (ISD), Texas' series 2020 unlimited-tax refunding bonds. At the same time, S&P Global Ratings affirmed its 'AA-' underlying rating on the district's existing general obligation (GO) debt. The outlook is stable. Revenue from an unlimited-ad valorem tax on all taxable property within the district secures the bonds. The district will use the proceeds to refund a portion of its outstanding debt for savings purposes. The 'AAA' program rating reflects our view of East Central ISD's eligibility for, and participation in, the Texas Permanent School Fund (PSF) bond guarantee program, which provides the security of a permanent fund of assets the district can