This chart shows the Consumer Price Index (CPI) Year-over-Year inflation rate — the percentage change in consumer prices compared to the same month one year earlier. When inflation is rising, purchasing power erodes and central banks typically respond by raising interest rates. The Monthly Change metric shows how the YoY inflation rate accelerated or decelerated from month to month. Historically, the highest US inflation occurred in the 1970s–1980s oil shock era, peaking near 15%. Data sourced from FRED (Federal Reserve Bank of St. Louis), series CPIAUCSL.