## Comprehensive Summary: Consumer Price Index (CPI) The Consumer Price Index (CPI) is not an organization, but rather a vital economic indicator produced by the U.S. Bureau of Labor Statistics (BLS)[1]. It measures the average change over time in the prices paid by urban consumers for a market basket of consumer goods and services, serving as the most widely used gauge of inflation in the United States[1][2]. The CPI is pivotal for economic analysis, policy-making, and financial decision-making across government, business, and individual sectors. ## What the CPI Does The CPI tracks price movements for a representative sample of goods and services—including food, housing, apparel, transportation, medical care, and education—purchased by urban households[1][2]. Data are collected monthly from about 23,000 retail and service establishments and 50,000 landlords or tenants across 75 urban areas[2]. The index uses expenditure weights derived from the Consumer Expenditure Survey to reflect actual spending patterns[2]. Notably, the CPI excludes rural populations, military personnel, and institutionalized individuals, focusing instead on urban consumers, who represent over 90% of the U.S. population[3]. ## History and Key Achievements The CPI was first introduced in the early 20th century to help measure cost-of-living adjustments for workers. Over the decades, it has evolved in methodology and scope, regularly updating its basket of goods and services to reflect changing consumer habits[1][6]. The CPI’s accuracy and reliability have made it a cornerstone for adjusting Social Security payments, tax brackets, and millions of private contracts, directly affecting the income of over 100 million Americans[2]. Its role in indexing wages, rents, and government benefits has helped mitigate the effects of inflation on vulnerable populations. ## Current Status and Notable Aspects As of October 2025, the CPI continues to be a critical tool for the Federal Reserve, policymakers, and financial market