Ada County homeowners could face a property tax increase for the first time in years as the Ada County Board of Commissioners works through a fiscal year 2027 budget under pressure from rising employee costs, shrinking state revenues, and years of absorbing expenses the county chose not to pass on to taxpayers. The board completed four days of budget presentations last week and has additional discussions scheduled for Tuesday at 1:30 p.m.
A Track Record of Restraint — Now Under Pressure
Since 2021, Ada County has stood apart from every other county in Idaho by consistently declining to collect the full amount of property taxes it is legally permitted to levy. That decision has left an estimated $33 million in taxpayers’ pockets over that period — a notable act of fiscal restraint during a time when the Treasure Valley was experiencing one of the fastest growth cycles in the country.
But county officials say the financial landscape has shifted in ways that make continuing that approach increasingly difficult. “This year is not the same,” said one county official involved in the budget process. “The pressure to keep the county on the correct path will require additional revenues in the form of property taxes or other revenues just to keep the lights on.”
That statement, attributed to budget discussions before the board, signals a meaningful shift in tone from a county that has long prided itself on leaving money on the table. Ada County residents searching for updates on Boise’s own property tax deliberations this budget season will find a similar theme emerging across the region: government costs are climbing faster than revenue in several Treasure Valley jurisdictions.
What Is Driving the Budget Strain
Several converging pressures are pushing Ada County’s FY2027 budget into difficult territory.
Employee costs are expected to climb by roughly $10 million, driven by health insurance, software support contracts, and potential cost-of-living adjustments for county workers. That figure alone would be significant in any budget year.
State inmate housing costs have quietly burdened the county for years. Ada County has spent more than $10 million housing state inmates over the past several years. Even accounting for a new state reimbursement rate applied retroactively across four years, the county would still have effectively subsidized $8.3 million of that cost — money that came from Ada County taxpayers, not the state.
Lost levy authority under House Bill 389 compounds the problem. That legislation capped new construction levy authority at 90 percent, costing Ada County an estimated $12 million in levy authority since 2022. The restriction was intended to provide relief to property owners in fast-growing areas, but it has constrained the county’s ability to generate revenue from the very growth driving its service demands.
Sales tax revenue flatlined in 2024 despite the county’s population continuing to grow. A new state law also redirected a portion of the county’s liquor tax revenue to fund Idaho State Police salary increases, removing another revenue stream Ada County had previously relied on. Interest revenue is projected to fall by $1.1 million in FY2027.
Adding long-term complexity: in 2028, Ada County will hit a 27th pay period — an event that occurs roughly every 11 years on bi-weekly payroll schedules — at a projected cost of just under $10 million. That looming obligation is already factoring into multi-year budget planning.
Impact on Ada County Residents and Taxpayers
Ada County added the equivalent of a small city’s worth of residents between 2025 and 2026 alone. More people means more demand for courts, law enforcement, road maintenance, permit processing, and county services of every kind — but the revenue streams meant to keep pace with that growth have not cooperated.
For homeowners across Boise, Meridian, Eagle, Kuna, Star, and Garden City, the prospect of a county-level property tax increase comes at a time when assessed values have already risen sharply. Any increase to the levy rate would stack on top of elevated valuations, amplifying the impact on household budgets.
What Comes Next
The Board of Commissioners has additional budget discussions scheduled for Tuesday at 1:30 p.m. A public budget presentation is set for July 21, giving residents an opportunity to review the county’s financial picture before decisions are finalized. The tentative budget is expected to be adopted in August, with levies set in September.
Ada County residents are encouraged to attend the July 21 public presentation or monitor the Ada County Commissioner meeting schedule for updates as the budget process moves toward adoption.