Which noncommissioned officer grades are specifically controlled by Congress?

The correct answer identifies that the grades of Senior Master Sergeant (SMSgt) and Chief Master Sergeant (CMSgt) are specifically controlled by Congress. This control stems from the fact that these ranks hold significant authority and represent the highest levels of enlisted leadership within the military structure. As such, their establishment and promotion criteria are directly influenced by legislative action to ensure that they align with the overall regulations and standards set for the Armed Forces.

This control allows Congress to oversee aspects such as the number of positions available at these grades and the requirements for promotion, ensuring that they maintain the appropriate balance and capabilities within the enlisted ranks. The emphasis on these particular grades reflects their critical roles in maintaining operational readiness and effectiveness in military operations. Other noncommissioned officer grades, while important, do not involve the same level of legislative oversight and flexibility.