I left the service ~40 years ago. There were various scenarios back in the day. Back then the total obligation to fulfilling the service obligation was six years. I did six years straight, so I had no further obligation after completing my active duty commitment. That said, I think it is likely senior enlisted people just sign yearly extensions. They have already met the minimum required time served unless they signed a contract for advanced training,
Walz was selected to attend the United States Army Sergeants Major Academy in early 2003. The course consisted of two years of correspondence coursework, followed by a two-week resident phase at Fort Bliss, Texas. Then he will serve for two years after graduation from the academy, or promotion to Sergeant Major or Command Sergeant Major, whichever is later.
From the original letter by Walz' fellow Sergeants Major:
Senior Non-Commissioned Officers initial and sign a Statement of Agreement and Certification upon enrollment. The State Command Sergeant Major or Army National Guard Command Sergeant Major counsels the soldier and certifies that the senior Non-Commissioned Officer understands their responsibilities.In the spring of 2004, Walz was selected by high level Command Sergeants Major to serve in the position of the Command Sergeant Major of the 1-125th Field Artillery Battalion. in the spring of 2004, he was selected by high level Command Sergeants Major to serve in the position of the Command Sergeant Major of the 1-125th Field Artillery Battalion.
In early 2005, a warning order was issued to the 1-125th Field Artillery Battalion, which included the position he was serving in, to prepare to be mobilized for active duty for a deployment to Iraq. This was not the actual deployment order, just a notice that Walz's unit was on the list to be deployed to Iraq in the future.
On May 16th, 2005 Walz quit. On October 12, 2005 Walz's unit was mobilized and deployed to Iraq in March 2006.
According to this timeline, Walz owed the Minnesota National Guard two years of service after completing the Command Sergeants Major Academy, but he dropped out and quit before completing his required post-academy two year commitment.
-PJ