Your question is a bit vague. Assuming you're referring to the basic Sergeant rank (E5), you could be looking at a number of things. Someone who is only an E5 after 20 years of service... they either weren't a particularly great NCO, or they might have gotten into a career field with a low turnover rate which denied them the opportunities for promotion that career fields with high turnover rates might have provided, or they may have simply been overlooked (it happens sometimes). If you're referring to someone who has held the rank of Sergeant for 20 years, you'd almost certainly be looking at someone in a reserve component (Army Reserve or National Guard).
An E-9 in the Army is the pay grade that denotes the rank of Sergeant Major, Command Sergeant Major, and Command Sergeant Major of the Army.
The E-6 paygrade in the Army is the rank of Staff Sergeant (SSG). Staff Sergeants typically have 6-8 years of service and are responsible for leading a platoon-sized element of 20-40 soldiers. They receive a base pay, plus various allowances and specialty pay based on their qualifications and assignments.
Level 20 Rank is: Sergeant First Class 2
A warrant officer is the highest rank of the soldiers rank, soldiers ranks range from private to warrant officer. Warrant officers normally would have done about 20 years of service and in the army. A warrant office is a RSM. Regimental Sergeant Major. They only have 1 RSM in a Battalion and the promotion of a RSM has to be approved by the Queen and signed for.
The answer is: 15 Years. The best place to find the answer of similar questions like this is in AR 601-280 Army Retention Program. The answer is found by seeking the rank's "Retention Control Point" (RCP). The RCP is the point at which you cannot stay elisted on Active Duty at the current rank past a certain time period. At times, the Dept. of the Army (DA) sends out messages to the Military to update or make changes to published regulations. One such message is found in (ALARACT Message 267-2008 effective 1 November 2008). See Below Private (PVT) - Private First Class (PFC) - 8 Years Corporal (CPL) / Specialist (SPC) - 10 Years Corporal (CPL) / Specialist (SPC) Promotable - 15 Years Sergeant (SGT) 15 Years Sergeant (SGT) Promotable - 20 Years Staff Sergeant (SSG) - 23 Years Staff Sergeant (SSG) Promotable - 26 Years Sergeant First Class (SFC) - 26 Years Sergeant First Class (SFC) Promotable - 29 Years First Sergeant (1SG) / Master Sergeant (MSG) - 29 Years First Sergeant (1SG) / Master Sergeant (MSG) Promotable - 32 Years Command Sergeant Major (CSM) / Sergeant Major (SGM) - 32 Years The following information can also be found in AR 601-280, Table 3-1 Retention Control Points For additional information you can also research AR 600-8-19 Enlisted Promtions and Reductions in Rank.
Better is a matter of opinion, but a sergeant major outranks a master sergeant or any other sergeant. There are other advantages in terms of pay and privilege. I am told that in the US Army only generals and sergeant majors have careers which last thirty years anymore. The rest are told to take their boots for a walk before then, even if they want to remain in service.
Depending on the individuals MOS (job), necessity for promotion based on the needs of the Army, their personal achievement's, prior positions held and their records it can take anywhere from 15-20 years. Typically promotion to E-9 Sergeant Major is between 14-18 years of service. The higher in rank you go the more competitive it gets because you are competing against thousands of other soldiers for less than 50 E-9 Sergeant Major slots for that year. The number of slots is based on the needs of the Army for that year.
Depending on the individuals MOS (job), necessity for promotion based on the needs of the Army, their personal achievement's, prior positions held and their records it can take anywhere from 15-20 years. Typically promotion to E-9 Sergeant Major is between 14-18 years of service. The higher in rank you go the more competitive it gets because you are competing against thousands of other soldiers for less than 50 E-9 Sergeant Major slots for that year. The number of slots is based on the needs of the Army for that year.
Reach Rank "Sergeant"(level 20) To get the 3rd title. (#3)
20 years or more of honorable service earns retirement. Payment is made every month. Amount depends on rank when retired.
The job of a Police Inspector is one rank above that of a Sergeant. Most Inspectors retire when they have reached their 20 year. However there is a Inspectors who will remain of the force longer.
Generally, greeting an officer by rank is acceptable, but "Sir" is preferred in the Army.EXAMPLE:"Good morning, Major" is acceptable, but "Good morning, Sir" is preferred.Here are some Army publications that address greetings and courtesies:Army Regulation 600-20, Army Command Policy, paragraph 4-3Army Regulation 600-25, Salutes, Honors and Visits of CourtesyField Manual 7-21.13, Customs, Courtesies, and Traditions, Chapter 4Department of the Army Pamphlet 600-60, A Guide to Protocol and Etiquettegenerally you use sir when referring to a HIGHER rank, but you can use their rank if they are lower then you, example:(lower rank) Hello, sir.(Higher rank) Hello sergeant. (your rank is captain.)