INEC officializes August CPI at 99.420 with a monthly drop of 0.11%

The National Institute of Statistics and Censuses (INEC) officialized that the Consumer Price Index (CPI) base June 2026 corresponding to August 2026 stood at 99.420, with a monthly variation of -0.11%. The data is published in La Gaceta No. 189 on Wednesday, October 7, 2026, via a notice with official reference IN202601129987. The accumulated variation over the last twelve months was -0.17%.

The notice is signed by David Adolfo Araya Amador, Deputy Manager of the INEC Management, and dated in San José on September 7, 2026. The text specifies that the officialization is carried out “based on studies conducted at the National Institute of Statistics and Censuses,” and that the index is calculated with the new base June 2026 = 100, which allows for the comparison of monthly levels under the same methodological reference.

The official data for August

The INEC summarizes the behavior of the indicator in three figures:

• Index level: 99.420.
• Monthly variation: -0.11%.
• Accumulated variation from September 1, 2025, to August 31, 2026 (twelve months): -0.17%.

The level below 100 reflects that the cost of the reference basket remains lower than that recorded in June 2026, the month taken as the base for the new series.

Who issues it and where it is published

The notice corresponds to the National Institute of Statistics and Censuses, the entity responsible for calculating and officializing the CPI in Costa Rica. The publication is made in the notices section of La Gaceta No. 189, corresponding to Wednesday, October 7, 2026, on page 132, under the official reference IN202601129987.

• Issuing body: National Institute of Statistics and Censuses (INEC).
• Signatory: David Adolfo Araya Amador, Deputy Manager.
• Notice date: September 7, 2026.
• Official medium: La Gaceta No. 189, October 7, 2026, p. 132.
• Official reference: IN202601129987.

Why it is relevant

The CPI is the reference indicator for the updating of specific taxes, public service tariffs, and indexed contracts, as provided in various regulations published in La Gaceta. Therefore, the officialization of the August data enables the adjustments that depend on the variation of the index and that must be calculated with figures already validated by the INEC.

The accumulated variation of -0.17% over twelve months confirms that the series remains in negative territory relative to the June 2026 base, a behavior that directly affects the calculation of quarterly and annual adjustments that use the CPI as a parameter.

The data for August 2026 is thus formally incorporated into the official series and available as a reference for calculations carried out by public institutions, municipalities, and private operators with indexation clauses.

Source: La Gaceta, No. 189 of October 7, 2026, Notices, page 132 (official reference: IN202601129987).