The simple version

Someone has to go out and find prices. When one of them cannot be found in a given month, the calculation does not leave it out.

It fills the hole with the average change for similar goods in the same area. If every similar one is missing too, the net widens to the region, and then wider still.

At the end of that chain, if nothing similar exists anywhere, last month's figure is carried forward unchanged. That last rung assumes no change at all.

The numbers

• Collection was suspended entirely in Lincoln, NE and Provo, UT in April 2025, and in Buffalo, NY in June 2025 (BLS, Notice of CPI collection reductions, last modified June 16, 2025)
• BLS states that these actions have minimal impact on the overall all-items CPI-U and CPI-W indexes, and may increase the volatility of subnational or item-specific indexes (same notice)
• BLS states that the number of imputed items increased in April because of these actions (same notice)
• Two tables are published: "Table 1: Imputation source for the commodities and services price survey, percent" and "Table 2: Imputation source for the housing survey, percent" (BLS, CPI imputation tables)
• Those notes state the tables do not represent an overall imputation rate for each survey (same tables)
• The series has been published since 2019, and October 2025 values are unavailable for both tables due to the 2025 lapse in appropriations (same tables)
• On the housing side, a recently vacant unit is estimated from the average rent change for units in the same location with a recent occupancy change, and a non-response is estimated within the same nominal rent class, low, medium or high, and location (same tables)

How a hole gets filled

There is a ladder, and each rung widens the net. The first rung is goods in the same category and the same place.

If all of those are missing, the category is held and the geography opens up, to the surrounding region and then past it.

Only when nothing in that category exists anywhere does the previous month's figure get carried forward. Each rung rests on a looser assumption than the one before.

The actual math the tables will not support

The tables report how often each rung of the ladder was used. They do not report what share of a whole survey was estimated rather than observed.

Those are two different things and only the first is published. No arithmetic on the first one produces the second.

The notes say so directly. So one overall share, presented as the amount of the inflation figures that is estimated, is not a number the source provides.

What this means

Filling a hole is not the same as making something up, and it is not nothing either. The method is published, the rungs are ordered, and the agency reports how often it reaches for each one.

The honest reading is narrower than either the alarm or the dismissal. The agency's own position is that the collection cuts barely move the headline figures while making small slices jumpier.

That matters for anyone reading one city or one category rather than the national number. The narrower the slice you care about, the more the substitution behind it is worth knowing about.

What this is NOT

This article explains what imputation means in the Consumer Price Index and what the agency's published imputation tables do and do not measure, using the Bureau of Labor Statistics imputation tables and its notice on collection reduction, both read on October 11, 2026. It states no monthly imputation figure, deliberately: the published tables report which substitution source was used rather than an overall rate, and their notes say so, so quoting a monthly value from them as an overall share would misuse the source. It is not a claim that the inflation figures are wrong, inflated, understated, or manipulated, and it takes no position on the agency's funding or staffing. It is not a forecast of any coming release. The characterisation of the collection cuts as having minimal effect on the headline measures and more effect on narrow ones is the agency's own, quoted from its notice, not our conclusion. The city suspensions described are those named in a notice last modified June 16, 2025, and later changes may exist that this article does not cover. This is not a political endorsement or criticism of anyone.

Sources

• U.S. Bureau of Labor Statistics, "Imputation" (CPI tables and notes), read October 11, 2026
• U.S. Bureau of Labor Statistics, "Notice of CPI collection reductions," last modified June 16, 2025, and "More information on CPI collection reductions," last modified July 29, 2025, both read October 11, 2026