Guides / The 17c formula, explained line by line
The 17c formula, explained line by line
Where it came from, how insurers compute it, and how to use it as a floor instead of a ceiling.
The "17c" formula comes from a Georgia regulation that was central to State Farm Mut. Auto. Ins. Co. v. Mabry, 274 Ga. 498 (2001). In Mabry, Georgia's Supreme Court confirmed that insurers must consider diminished value when settling first-party claims, and the DOI's proposed methodology — labeled 17c in the record — became the industry's default DV algorithm.
The product's implementation multiplies: pre-accident value × damage factor (structural/airbag 0.25, major 0.125, minor 0.05) × mileage modifier (1.0 under 20k miles, stepping down to 0 above 100k) × value modifier (0 under $5,000, up to 1.5 over $25,000). The exact bracket boundaries are shown in your estimate report.
Understand what 17c is designed to do: it is a formula an insurer can apply consistently, and its multipliers usually produce conservative numbers. That is why negotiating only against 17c tends to leave money on the table. Pair it with real market evidence — listings of comparable clean-history vs. accident-history vehicles — and demand the larger, evidenced number.
How to fight a 17c-based offer
- Get your exact computation in writing and check each factor against the repair invoice and mileage
- Collect 2–3 comparable listings showing the clean-vs-accident price gap
- Present the market evidence in your demand letter (our Full Kit does this automatically)
- If the insurer stalls, escalate: follow-up letter, then the policy's appraisal clause, then small-claims court