If you are under the National Master Agreement, there is a COLA formula in Article 33, but it doesn't apply to anyone still in progression.
The formula isn't easy to trigger. Inflation has to increase by four percent or so, otherwise there is no cost of living adjustment.
The last COLA in recent memory was 12 cents in 2006.
When a COLA is paid, it is above and beyond ( in addition to) any other raises you are entitled to, and becomes a fixed part of the wage base from that moment on.
Article 33
Cost-of-Living (COLA)
All seniority employees who have completed their appropriate wage progression schedule shall be covered by the provisions of a cost-of-living allowance, as set forth in this Agreement.
Employees who have not completed their appropriate wage progression on the effective date of a COLA increase, shall receive the adjustment on a prospective basis on the date they complete their wage progression schedules.
The amount of the cost-of-living allowance shall be determined as provided below on the basis of the "Consumer Price Index for Urban Wage Earners and Clerical Workers, CPI-W (Revised Series using 1982-1984 Expenditure Patterns), All Items (1982-84= 100), published by the Bureau of Labor Statistics, U.S. Department of Labor" and referred to herein as the "Index".
Effective August 1, 2009, and every August 1 thereafter during the life of the Agreement, a costof-living allowance will be calculated on the basis of the difference between the Index for May 2009 (published June 2009) and every May thereafter, and the base Index for May 2008 (published June 2008) and every May thereafter, as follows:
For every 0.2 point increase in the Index, over and above the base (prior year’s) Index plus 3.0% there will be a 1 cent increase in the hourly wage rates payable on August 1, 2009, and every August 1 thereafter. These increases shall only be payable if they equal five ($.05) cents in a year.
All cost-of-living allowances paid under this Agreement will become and remain a fixed part of the base wage rate for all job classifications. A decline in the Index shall not result in the reduction of classification base wage rates.
Mileage paid employees will receive cost-of-living allowances on the basis of .25 mills per mile for each 1 cent increase in hourly wages, subject to the threshold set forth above.
In the event the appropriate Index figure is not issued before the effective date of the cost-of-living adjustment, the cost-of-living adjustment that is required will be made at the beginning of the first pay period after the receipt of the Index.
In the event that the Index shall be revised or discontinued and in the event the Bureau of Labor Statistics, U.S. Department of Labor, does not issue information which would enable the Employer and the Union to know what the Index would have been had it not been revised or discontinued, then the Employer and the Union will meet, negotiate, and agree upon an appropriate substitute for the Index.
Upon the failure of the parties to agree within sixty (60) days, thereafter, the issue of an appropriate substitute shall be submitted to an arbitrator for determination. The arbitrator’s decision shall be final and binding.