What is IGP-M and why has it been used in rent contracts?

The General Market Price Index, Market version, is calculated by Fundação Getulio Vargas. Its composition gives substantial weight to wholesale prices, while also including consumer prices and construction costs.

This broad basket explains why IGP-M can move far above or below IPCA. Exchange rates, commodities and producer prices can affect it before the same movement reaches household consumption.

FGV IBRE reported IGP-M at -0.22% in August 2026, 1.85% year to date and 2.16% over 12 months in its August 28 release.

Why it became associated with rent

IGP-M became common in long-term contracts, especially rent and service agreements. That historical practice does not make it a perfect measure of a tenant's cost of living.

Before accepting an adjustment, read the clause, check the reference period and compare the result with IPCA and current market rent. Contract interpretation may require professional legal advice.

How to read accumulated IGP-M

• Confirm the exact start and end months in the contract.
• Use the accumulated index for that period rather than one isolated month.
• Remember that negative years offset part of previous increases through compounding.
• Compare the adjusted amount with similar properties before negotiating.