Standard&Poor's Ratings Services assigned its 'A-1+' rating to Houston's series E-1 (remarketed) general obligation (GO) commercial paper (CP) notes. At the same time, Standard&Poor's affirmed its 'A-1+' rating on the city's previously issued GO CP notes. The rating reflects our view of the city's strong general creditworthiness ('AA+' GO debt rating), and a limited ad valorem tax levied on taxable property in the city that secures the notes. As of May 31, 2015, there was about $141.9 million of outstanding CP notes across all of Houston's GO CP programs. Houston is replacing the liquidity agreement that previously supported the E-1 notes by entering into a credit agreement with Citibank N.A. effective July 15, 2015. The agreement