Idaho's insurance office has been plain about lost value on your own policy. For a diminished value claim in Idaho, that answer sends most drivers to the other driver's insurer instead.
Your Own Policy Comes First
The Idaho Department of Insurance is direct. Your company need not pay for lost value unless your policy says so. The same page adds that the department has no authority to set the value of your car. Pull out your policy and read the part on physical damage line by line.
Claiming Against the At-Fault Driver
The MWL chart of all 50 states found no Idaho ruling on a third-party claim for lost value. The claim rests on the general right to be paid for damage someone else caused. That is still a real claim, and an adjuster can pay it.
Because there is no case to point to, the proof does the work. Get a diminished value appraisal that compares the market value before the crash with the value after repairs. Then put the figure in writing with a demand letter.
Fault and the Three-Year Clock
Under Idaho Code § 6-801, you can collect only while your negligence is less than the other driver's. Split the blame evenly and you get nothing.
The deadline is three years. Idaho Code § 5-218 covers actions for injuring goods or chattels. A damaged car fits.
Two Limits Set at $15,000
Idaho requires at least $15,000 in property damage liability coverage, per the department's coverage page. If the other driver carries only that, it is the ceiling for your repair and lost value together.
The small claims limit happens to match. The Idaho Court Assistance Office says a person or business can sue for up to $15,000 there. Bring the appraisal and the repair bill to the hearing. If an insurer will not respond, file through the department's complaint page. Across the border, Washington has its own rules.