The 'A' rating on East Pennsboro Area School District, Pa.'s GO bonds reflects Pennsylvania's state aid withholding provision established under Act 150 of the Public School Code. If the school district is unable to pay principal or interest when due, the secretary of education will withhold the district's state aid and remit the funds directly to the paying agent. For the guarantee program to be considered a credit substitution, annual state aid must be at least equal to future maximum annual debt service. The stable outlook reflects the strength of the Pennsylvania State Aid Intercept structure.