How Often Is CPI Calculated? Monthly Release and Revisions

The Bureau of Labor Statistics calculates the Consumer Price Index once a month at the national level, releasing each month’s figures at 8:30 a.m. Eastern Time roughly two to three weeks after the reference month ends.¹ Regional and local indexes come out on slower cycles — some bimonthly, some semi-annual — depending on the size of the area. So when people ask how often CPI is calculated, the short answer is monthly for the national headline number, less often for everything smaller.

What Arrives in the Monthly Release

Each monthly release contains three national indexes, each measuring a different population or using a different formula:

CPI-U, for all urban consumers, covers about 93 percent of the U.S. population and is the index most people mean when they refer to “the CPI.”²
CPI-W, for urban wage earners and clerical workers, covers roughly 29 percent of the population — households where more than half the income comes from clerical or wage jobs and at least one earner worked 37 or more weeks in the prior year. Social Security cost-of-living adjustments are tied to this version.³⁴
C-CPI-U, the Chained CPI for All Urban Consumers, accounts for consumers substituting between goods when prices change. The IRS uses this version to adjust federal income tax brackets each year.⁵

The same report breaks the numbers into component categories. The “all items” figure, sometimes called headline CPI, covers everything including food and energy. A parallel “all items less food and energy” figure strips those two volatile categories out to show underlying price trends. Both appear every month.

When the Monthly Number Lands

The BLS publishes its release calendar in advance so markets, agencies, and businesses know exactly when fresh data will hit. Every release is 8:30 a.m. Eastern Time, and the gap between the reference month and the release is typically 10 to 13 business days. December 2025 data, for example, was published on January 13, 2026, following the same pattern as the rest of the year.¹

The 2026 release dates are:¹

January data: February 13, 2026
February data: March 11, 2026
March data: April 10, 2026
April data: May 12, 2026
May data: June 10, 2026
June data: July 14, 2026
July data: August 12, 2026
August data: September 11, 2026
September data: October 14, 2026
October data: November 10, 2026
November data: December 10, 2026

How Often Local and Regional Numbers Come Out

The national monthly cadence does not carry over to every geography. The BLS publishes monthly indexes for the four Census regions, the nine Census divisions, and a limited set of large metro areas.⁶ Most other metropolitan areas update on a bimonthly cycle, assigned to either even- or odd-numbered months. Philadelphia, Detroit, and Houston are priced on even-numbered months; Boston, Dallas, and Denver are priced on odd-numbered months. Some smaller metros only get semi-annual updates, and the component detail available for local figures is thinner than what the national report carries.⁷

If you are using a city-level CPI for a lease adjustment or business plan, confirm which cycle your metro falls on, because the figure you want may lag the national number by up to two months.

How the BLS Gathers Data Fast Enough to Publish Monthly

BLS staff visit or contact thousands of stores, service providers, rental units, and medical offices every month, recording about 80,000 prices.⁷ Prices are collected throughout the month rather than on a single snapshot date, which helps the index reflect the broader market and limits distortion from short-lived sales.⁶

Monthly, though, doesn’t mean every item in every place. Food, energy, and a handful of other categories are priced every month nationwide. For most other goods and services, prices in the three largest metro areas (New York, Los Angeles, and Chicago) are also collected monthly, but everywhere else those items are priced only every other month.⁷

Housing Runs on a Six-Month Clock

Housing is the largest single component of the CPI, and its rent data is collected on a six-month rotation. The BLS splits its housing sample into six panels, each tied to a pair of months: Panel 1 is surveyed in January and July, Panel 2 in February and August, and so on through Panel 6 in June and December.⁸ Because leases tend to lock rent in for months at a time, surveying less frequently lets the BLS maintain a larger sample. Each six-month price change is converted into a monthly figure using a mathematical formula that takes the sixth root of the six-month change.⁹ That converted figure feeds into every monthly national index, even though no single housing unit is contacted that often.

What Gets Revised After Publication

Once CPI-U or CPI-W is out, that month’s figure stands. Neither is revised. The Chained CPI-U is different. Because the C-CPI-U formula needs spending-pattern data that takes time to assemble, the BLS first publishes a preliminary value, issues three interim revisions, and only releases the final figure 10 to 12 months after the initial release.¹⁰ If you are using C-CPI-U for a contract or analysis, check whether you have a preliminary or final value.

Seasonal adjustment factors are recalculated once a year, with the release of January CPI data in February. Each annual recalculation revises seasonally adjusted indexes for the prior five years. Factors covering January 2021 through December 2025, for instance, were published on February 13, 2026.¹¹ Older seasonally adjusted figures in your records can shift slightly after each February recalculation.

Why the Monthly Schedule Matters

The monthly cadence drives real-world adjustments. Social Security COLAs are set each year by comparing the third-quarter CPI-W average (July through September) to the third-quarter average from the last year a COLA took effect; the resulting percentage sets the following January’s benefit increase.¹² The IRS uses C-CPI-U figures published through August of the prior year to adjust federal income tax brackets, the standard deduction, and dozens of related thresholds.⁵ The principal value of Treasury Inflation-Protected Securities adjusts with the CPI-U, so each monthly release moves both TIPS prices and the dollar amount of their semiannual interest payments.¹³

Many commercial leases and labor agreements also tie escalation clauses to a specific CPI index, and the BLS recommends spelling out exactly which one — CPI-U or CPI-W, which geography, seasonally adjusted or not.¹⁴ Because a December figure typically does not publish until mid-January, any clause tied to the prior year’s data has to leave room for that lag.

1
U.S. Bureau of Labor Statistics. Schedule of Releases for the Consumer Price Index
2
U.S. Bureau of Labor Statistics. Handbook of Methods Consumer Price Index Design
3
U.S. Bureau of Labor Statistics. Consumer Price Index Summary – 2026 M01 Results
4
Social Security Administration. CPI for Urban Wage Earners and Clerical Workers
5
Office of the Law Revision Counsel. 26 U.S. Code 1 – Tax Imposed
6
U.S. Bureau of Labor Statistics. Consumer Price Index Overview
7
U.S. Bureau of Labor Statistics. Consumer Price Index About Questions and Answers
8
U.S. Bureau of Labor Statistics. CPI Rent and Owners Equivalent Rent (OER) Questions and Answers
9
U.S. Bureau of Labor Statistics. Measuring Price Change in the CPI: Rent and Rental Equivalence
10
U.S. Bureau of Labor Statistics. Frequently Asked Questions about the Chained Consumer Price Index for All Urban Consumers (C-CPI-U)
11
U.S. Bureau of Labor Statistics. Consumer Price Index Methods Seasonal Adjustment
12
Social Security Administration. Latest Cost-of-Living Adjustment
13
U.S. Treasury Fiscal Data. TIPS and CPI Data
14
U.S. Bureau of Labor Statistics. Writing an Escalation Contract Using the Consumer Price Index