I hit a deer and filed a car insurance claim to recoup some of the mostly cosmetic repair costs — but now my insurer has declared my vehicle a total loss. Can I fight this?

In that case, your insurer will cut you a check for your car’s cash value before the damage. But that only does you so much good if the payout you receive won’t cover the cost of a new vehicle.

The question is, are you out of luck in this situation? Or can you fight your insurer’s decision?

Why cars are declared totaled

An insurer will generally total a car when the cost to fix it exceeds its value at the time of the incident. If your car was only worth $4,000 at the time of an accident and you're looking at $4,500 in body work to fix it, it doesn't make sense for your insurer to pay the higher amount when it can declare your vehicle totaled instead.

However, sometimes things aren't as clear cut. It's possible that an insurer will total a car even if the repair costs are lower than the vehicle's value.

Insurance companies may do this because it's not always possible to determine how badly a car is damaged — and how expensive the fix will be — before the repairs begin. So insurers can argue that they shouldn't have to take the risk of having their repair costs exceed a vehicle's value.

Some states have laws that define a totaled vehicle based on certain criteria. But insurers may opt for lower thresholds of damage that will benefit them financially.

If your car is totaled, your payout will represent its actual cash value. Insurance companies use different criteria to calculate actual cash value, including age, mileage, condition and modifications you may have made.

Fighting your insurer's decision to total your car

When your car gets totaled, the payout you get often won't be enough to replace your vehicle with another one. But you should know that you're able to appeal your insurance company's decision to total your car.

To be successful, though, you'll need to take a few steps. First, you may need to get an independent appraisal to prove that your car's value is higher than your insurer says it is. Next, you may need to go out and get estimates from different auto shops for fixing the damage. If you can make the numbers work in your favor, you may be able to get your insurer to change its mind.

For example, say your insurer determines that it will cost $4,500 to repair your car, but it's only worth $4,000. If you can get an appraisal showing your car is actually worth $5,000 and an estimate putting the cost of repairs at $3,000, you may have success.

When you decide to keep a totaled car

You can likely also negotiate to keep a car that your insurance company decides to total. In that case, the car is considered a salvage vehicle. You can still expect a payout from your insurance company, but it may be reduced because your insurer won't be able to sell your car for parts if you opt to keep it.

You should also know that if you're still paying off your car, you're on the hook for any remaining loan payments even once your insurer declares it totaled. You can, however, use your insurance payout to pay off your loan. But be aware, getting insurance for a salvage title turned rebuilt vehicle is more challenging and more expensive, so you may not be better off taking this route.