The Army, Air Force and Marine Corps offer the master sergeant rank. While all branches follow the same pay grade structure on the same pay scale, salary can differ when looking at rank. Each branch assigns a rank to the pay grade it deems appropriate. For example, an Army master sergeant is considered grade E-8 and an Air Force master sergeant is considered an E-7 and thus paid less.
On the military pay scale, the basic monthly pay for an E-8 with over 18 years of service in 2014 was $4,767.60. An E-7 with the same years in made $4,323.90. Therefore, an Army master sergeant, E8, with 18 years made $4,767.60 and an Air Force master sergeant, E-7, with the same time made $4323.90. Similar to the Army, the Marine Corps' master sergeant rank is considered an E-8 and thus is paid the same as an Army master sergeant. Note that pay varies depending on length of service. An E-8 with over eight years service in 2014 made $3,959.40. An E-7 with over eight years made $3,594.90.
Service members get additional benefits such as a housing allowance. The rate you receive as a master sergeant depends on whether you are an E-8 or E-7. The amount is also determined by location. For example, an E-8 with dependents based in Ketchikan, Alaska, in 2014 made $2,310 per month; an E-7 made $2,013. The military offers special incentive pay classifications as well, and some are based on factors other than rank. For example, hardship pay is offered to service members living in "arduous" circumstances. The amount you receive depends on the level of hardship, not rank. The pay ranges from $50 to $150 per month.