Chief petty officer (United States)

Chief Petty Officer (CPO) is the seventh enlisted rank (with the pay grade E-7) in the United States Navy and U.S. Coast Guard, is above Petty Officer First Class and below Senior Chief Petty Officer. The term "rating" is used to identify enlisted job specialties.

Enlisted personnel are divided into three subdivisions or levels, the lowest level being non-rated members without a designated occupation (E-1 through E-3) who are in training, known as an apprenticeship, to become rated; becoming a rated sailor and advancing to E-4 is dependent on graduating from a specialty school that define what the enlisted is rated for.

The second level is rated sailors who are Petty Officers (E-4 through E-6) who are NCOs or non-commissioned officers. Finally, the third level are Chief Petty Officers (E-7 through E-9) that are SNCOs or senior non-commissioned officers and part of the rated force and considered extremely knowledgeable about their particular rating.

The term rating is used to identify the career field of a Chief Petty Officer. For example, the title of a Chief Petty Officer in the Master-at-Arms rating would be spoken or spelled out as Chief Master-at-Arms. The title would be abbreviated MAC. The grade of Chief Petty Officer was established on 1 April 1893 in the United States Navy. The United States Congress first authorized the Coast Guard to use the promotion to Chief Petty Officer on 18 May 1920. Chief Petty Officer is also the final cadet grade in the United States Naval Sea Cadet Corps.

Prior to 1958, Chief Petty Officer was the highest enlisted grade in both the U.S. Navy and U.S. Coast Guard. This changed with the passage of Pub. L. 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 called Senior Chief Petty Officer (SCPO) and the new E-9 pay grade Master Chief Petty Officer (MCPO), with the first selectees promoting to their respective grades in 1959 and 1960.

Prior to establishment of the E-8 and E-9 grades, Chief Petty Officers could typically serve in uniform for 30 or more years.