FY 2027 Inflation Factor for Mill Levy Calculation

Published April 9, 2026

FY 2027 Inflation Factor for Mill Levy Calculation

The Montana Department of Revenue MACo calculated the FY 2027 inflation factor for mill levy at 2.97%.

Per 15-10-420, MCA, “a governmental entity that is authorized to impose mills may impose a mill levy sufficient to generate the amount of property taxes actually assessed in the prior year plus the average rate of inflation for the prior 3 years, not to exceed 4%.”

Additionally, the Department of Revenue shall, “calculate the average rate of inflation for the prior 3 years by using the consumer price index (CPI), U.S. city average, all urban consumers, using the 1982-84 base of 100, as published by the bureau of labor statistics of the United States Department of Labor.”

The average rate of (compounding) inflation was determined by taking the cubed root of the CPI for December 2025 (324.054) divided by the CPI for December 2022 (296.797), and subtracting one.

If you have any questions, please contact Dylan Cole with DOR’s Tax Policy and Research Division by way of email at dylan.cole@mt.gov or by phone at 406-444-6634.

If you would like to speak with someone at MACo, please reach out to Nancy Everson, Governmental Finance Director, by way of email at neverson@mtcounties.org or by phone at 406-441-5486.