Cost guide · Water treatment
How much does a reverse osmosis system cost installed in 2026?
Typical range
$400 – $1,200
for under-sink residential installation
Under-sink reverse osmosis (RO) system installation costs $400–$1,200 in 2026. Whole-house RO systems run $3,500–$8,000. Annual filter maintenance adds $75–$200; membrane replacement every 2-3 years adds $75–$200.
Why the range is wide
Reverse osmosis systems use a semi-permeable membrane to remove dissolved solids, heavy metals, fluoride, and most contaminants from water. Most residential applications are point-of-use (under-sink for drinking water and cooking). Whole-house RO is significantly more expensive and produces wastewater at higher rates, making it less common for residential use.
Factors that affect price
System type
Standard 4-stage under-sink RO: $400-$700 installed. Premium 5-6 stage with mineral re-injection: $700-$1,200. Tankless RO systems: $800-$1,500. Whole-house RO: $3,500-$8,000+.
System quality and brand
Major brands (Aquasana, iSpring, APEC): mid-range pricing. Premium brands (Reverse Osmosis Revolution, GE): higher quality + higher cost. Budget no-name systems: lowest cost but variable reliability.
Plumbing modifications
Standard under-sink installation with available water supply: standard pricing. Adding dedicated faucet (often included in install): +$100-$200. Connecting to refrigerator water/ice maker: +$100-$250.
Pre-treatment requirements
Typical city water: no additional pre-treatment needed. Well water with high TDS or iron: pre-treatment may be required to protect membrane, +$300-$1,000.
Annual maintenance contract
Filter replacement service contract: $150-$350/year covers parts + labor for annual filter changes. DIY filter replacement: $50-$100/year in parts.
Regional variation
Areas with high TDS municipal water (parts of Florida, Texas, Arizona, southern California) drive higher RO demand for drinking water quality. Pricing similar regionally; demand intensity varies.
DIY vs pro
Under-sink RO installation is within capable DIY scope — most kits include detailed instructions and the work is mostly plumbing connections. Realistic time investment: 3-5 hours for capable DIY vs 1-2 hours professional. Whole-house RO installation requires more substantial plumbing work and is generally professional service.
Reverse osmosis system — frequently asked
Run a water treatment business that quotes reverse osmosis system jobs in 5 minutes
ServiceGrid: dispatch, quoting, invoicing, customer portal, and built-in phone system. 14-day free trial, no credit card.