<P> Prior to 1958, Chief Petty Officer was the highest enlisted rank in both the U.S. Navy and U.S. Coast Guard . This changed on 20 May 1958 with the passage Public Law 85 - 422, the Military Pay Act of 1958, which established two new pay grades of E-8 and E-9 in all five branches of the U.S. Armed Forces . In the U.S. Navy and U.S. Coast Guard, the new E-8 pay grade was titled Senior Chief Petty Officer (SCPO) and the new E-9 pay grade as Master Chief Petty Officer (MCPO), with the first selectees promoting to their respective grades in 1959 and 1960 . </P> <P> Prior to establishment of the E-8 and E-9 grades, Chief Petty Officers could typically serve in uniform for 30 or more years . </P> <P> Shortly following establishment of the E-8 and E-9 grades, service limits currently known as High Year Tenure (HYT) were established by pay grade . Although these limits periodically flex based on Fleet manpower requirements, current HYT limits restrict Chief Petty Officers not selected for promotion to Senior Chief Petty Officer to 24 years of service, after which they face mandatory retirement . </P> <P> Similar limits of 26 years for Senior Chief Petty Officers and 30 years for Master Chief Petty Officer are currently used, with a smaller core of Master Chief Petty Officers serving in Command, Force or Fleet Master Chief Petty Officer positions in the Navy and Area or the Coast Guard Reserve Force Master Chief in the Coast Guard, being eligible to remain in uniform for 32 to 35 years and with the Master Chief Petty Officer of the Navy and the Master Chief Petty Officer of the Coast Guard being permitted to remain in uniform until reaching 38 years of service . </P>

Who signed the general order that recognized chief petty officer as an official navy rate