The Warrant Officer Management Act (WOMA) of 1991 initiated sweeping changes in warrant officer personnel management. The WOMA authorized a CW5 grade with specific pay and allowances, adopted a single Active Duty List System, and eliminated the dual temporary and permanent promotion system. All future promotions were to be permanent, using standardized procedures and tenure for Regular Army (RA) personnel and active duty reservists. As in the commissioned officer system, all warrant officers the Army had passed over twice for promotion would retire or be separated with separation pay.
Which shows how old and out of the loop I am.
Did find this though: WO News, July 2005.
Tenure AC CW4s: Current policy requires that AC CW4s who are 2-time non-selects for CW5 be separated, unless they are selected for continuation (SELCON), and then they can only serve to 24 years WO service (or 30 years total service, whichever occurs first). A legislative change proposal has been submitted that removes the separation and SELCON requirement for CW4s. Additionally a change has been submitted to remove the 30 years total service limit and soldiers would only be limited by total warrant officer service, which would still be capped at 24 years of WO service for CW4s and below. A legislative change package has been submitted to change the law, and the Assistant Secretary of the Army (Manpower & Reserve Affairs) has been asked to suspend the separation policy (which he may do in wartime) until the law is changed.
War tends to have that sort of effect...