Setting Recharge Rates for Vivarium Core Facilities
Recharge rate calculation follows federal cost principles:
Cost categories: Include all allowable direct costs — personnel (salaries, benefits), supplies (food, bedding, reagents), equipment depreciation, utilities, and consumables. Exclude unallowable costs like entertainment, alcohol, and lobbying.
Cost recovery target: Federally funded facilities must target break-even (100% recovery). Some institutions set rates at 80-90% with the shortfall covered by institutional funds. Never exceed 100% recovery for federal grants.
Cage-type multipliers: Differentiate rates by cage type. Standard static cages are the baseline (1.0×). IVC cages typically cost 1.2-1.5× due to HEPA-filtered air systems. Metabolic cages, large animal housing, and BSL-2/3 containment cages have higher multipliers.
Census sensitivity: Fixed costs (personnel, equipment, utilities) don't change with census, so per-diem rates are highly sensitive to census fluctuation. A 20% census drop can require a 25% rate increase to maintain cost recovery. Build this sensitivity into annual rate reviews.
Annual rate review: OMB requires periodic review. Compare actual costs and cage-days against projections. Carry surplus or deficit forward and adjust next year's rate accordingly.