Core CPI — the Fed's preferred read on inflation.
Core CPI strips food and energy out of the headline index to reveal the underlying trend. It's the figure the Federal Reserve watches most closely, the figure bond markets price off of, and the figure that ultimately drives monetary policy.
Core CPI year-over-year
The 12-month percent change in CPI-U excluding food and energy. The Fed's 2% inflation target is technically tied to PCE, but core CPI moves in tight tandem and is the high-frequency read most market participants track.
FRED:CPILFESL · U.S. Core CPI (Index, SA, ex Food & Energy)
MonthlyWhy core matters more to the Fed than headline
The Federal Reserve is required by its dual mandate to deliver maximum employment and stable prices. The numerical interpretation of "stable prices" has been a 2% target — formally on the PCE price index — since 2012. But when Fed officials describe what kind of inflation they're trying to influence, they almost always reach for the core measures.
The logic is straightforward. Monetary policy works with long, variable lags — twelve to eighteen months at minimum. A rate hike today does almost nothing to next week's gasoline price, which is set by global crude markets, refining margins, and seasonal demand. It does, however, eventually slow the labor market, which feeds into wages, which feed into the price of services — exactly the categories core CPI is built to highlight.
The other reason is statistical. Energy CPI has historically swung by ±20% year-over-year. Food has often moved ±5%. If the Fed reacted to every commodity blip, monetary policy would be wildly procyclical. Filtering those out produces a cleaner signal.
This doesn't mean headline CPI is irrelevant to the Fed. When commodity-led inflation persists long enough, it can pass through to wages and core services — the so-called second-round effects that policymakers fear most. The 1970s are the textbook case: oil shocks repeatedly leaked into the broader price level, partly because the Fed accommodated them.
The lesson Fed officials draw from that period is to watch for divergence. When headline and core move together, you have a broad-based inflation problem. When headline runs above core but core stays anchored, the problem is likely a commodity-specific shock that will fade. When core runs above headline — as it did briefly in 2023 — the underlying trend is the dominant story and energy is a temporary disinflationary force.
For policymakers, the practical question each month becomes: what does this print say about three to six months from now? Core gives the cleanest answer.
Sticky vs. flexible prices
The Atlanta Fed's sticky-price CPI splits the basket by how often prices typically change. Sticky items reprice less than once every 4.3 months; flexible items reprice more often. The distinction is more useful than "core vs. headline" for spotting persistence.
| Bucket | Examples | Behavior |
|---|---|---|
| Sticky core | Rent, OER, medical services, education, insurance, restaurant meals | Slow-moving, trend-following, hard to disinflate quickly |
| Flexible core | Used cars, apparel, lodging away from home, airline fares | Repricing within weeks, often reverses |
| Sticky headline | Tobacco, recreation services | Slow drift |
| Flexible headline | Gasoline, fresh produce, natural gas utility | High-frequency volatility |
"Supercore" services — the new Fed favorite
Since the post-pandemic inflation surge, Federal Reserve officials including Chair Jerome Powell have increasingly pointed to one specific cut of the data: core services excluding shelter. The shorthand "supercore" was popularized by Wall Street researchers and has stuck.
The reasoning is layered. Shelter, despite being inside core, is dominated by methodological lags. The BLS measures rent and owners' equivalent rent (OER) using surveys with smoothing that means today's market rents take 12 to 18 months to fully appear in the official index. So shelter is technically core, but in real-time, it's a slow-moving caboose telling you what rents did a year ago.
Strip out shelter and what remains in core services — medical services, transportation services, recreation services, education, communication — is closely tied to wages. Wages are the single largest cost for service businesses. If the labor market is tight, supercore should rise. If labor cools, supercore should ease. The Fed sees this measure as the cleanest read on whether its rate hikes are working.
The risk in over-relying on supercore is that it's noisy month to month — categories like airline fares and lodging can swing by several percentage points on idiosyncratic factors. A three-month moving average is the standard smoothing approach.
For deeper context, see our CPI housing page on shelter methodology and the CPI categories hub for the full breakdown.
Core vs. headline — when they diverge
FRED:FPCPITOTLZGUSA · U.S. CPI YoY (% change, SA, Monthly)
Monthly · Compare with core aboveLooking at the two series side by side reveals the historical pattern. In commodity shock periods — 1973–74, 1979–80, 2008, 2021–22 — headline ran sharply above core. In disinflation periods, headline usually fell faster than core, sometimes giving false hope that the problem was solved. The 2022–23 episode followed this template precisely: headline peaked at 9.1% in June 2022 and fell rapidly through 2023, while core proved much stickier.
The implication for forecasting: extrapolating from a single soft headline print into a sustained disinflation thesis is risky if core has not also softened. The reverse is also true — a hot headline number driven by oil typically won't keep the Fed hawkish if core continues to ease.
Frequently asked questions
Why does Core CPI exclude food and energy?
Food and energy prices are highly volatile month to month, often driven by weather, geopolitics, or supply shocks rather than underlying demand. Stripping them out reveals the underlying inflation trend that monetary policy can actually influence.
Why does the Federal Reserve focus on core inflation?
The Fed targets persistent inflation, not transitory price spikes. Core CPI and core PCE filter out the most volatile categories so policymakers can judge whether inflation is becoming embedded in the broader economy.
What is 'supercore' inflation?
Supercore refers to core services excluding shelter. It captures wage-sensitive service prices — restaurants, recreation, transportation services — that the Fed believes most directly reflects labor-market tightness.
What's the difference between sticky and flexible prices?
Sticky prices (rent, insurance, medical) change infrequently and tend to follow trend inflation. Flexible prices (gasoline, food, used cars) reprice often and reflect short-term shocks. Sticky-price CPI is a useful gauge of underlying momentum.
How is Core CPI calculated?
Core CPI is computed by re-weighting CPI-U with the food and energy components removed. BLS publishes both the index level and the year-over-year percent change in the monthly release.
Can headline and core CPI diverge for long?
Yes. In commodity-led inflation episodes (oil shocks, food crises), headline can run well above core for months or even years. Eventually the two converge unless second-round effects pass commodity costs through to other categories.