Seasonal adjustments are made annually. The new seasonal adjustments are effective with the January reports. The seasonal adjustment factors are developed by the U.S. Department of Commerce and provided to ISM in January.

The indexes that are currently seasonally adjusted are:

• Manufacturing: New Orders, Production, Employment and Supplier Deliveries
  
  
• Non-Manufacturing: Business Activity, New Orders, Employment and Prices

Current Seasonal Adjustment Information

• 2013 Revisions and Seasonal Adjustment Factors (News Release)
  
  
• Index Comparison - Excel Format