S&P Global Ratings has raised its underlying rating for credit program on East Central Independent School District (ISD), Texas' general obligation (GO) debt to 'AA-' from 'A+'. At the same time, S&P Global Ratings assigned its 'AAA' long-term rating and 'AA-' underlying rating for credit program to the district's series 2016 unlimited tax school building bonds. The outlook on both ratings is stable. The upgrade is based on the district's moderate debt burden, which has remained relatively stable despite ongoing debt issuances. The long-term program rating reflects the district's qualification for, and the guarantee provided by, the Texas Permanent School Fund. The program provides the security of a permanent fund of assets that could be used to meet debt service