The number the Federal Reserve cares about most is about to get a makeover. The Bureau of Economic Analysis is changing how it calculates prices for three components of the Personal Consumption Expenditures price index, the Fed’s preferred inflation gauge, and the revisions could shave a meaningful chunk off recent inflation readings.
The updated methodology will take effect on September 30, 2026, and will apply retroactively to data going back to 2021. In English: five years of inflation history are about to be rewritten.
What’s actually changing
The BEA is revising its price calculations for three specific categories: portfolio management and investment advice services, legal services, and computer software and accessories. The fix involves swapping in more robust data sources from the Producer Price Index and composite indices, replacing previous methodologies that relied on less representative inputs.
The timing is deliberate. The September 30 effective date coincides with the BEA’s annual revisions to gross domestic product data, making this part of a broader effort to clean up the national economic scoreboard in one coordinated sweep.
