When an insurer pays a claim caused by someone else, the payment is not the end of the matter. The insurer generally acquires the right to pursue the responsible party.
The insurer steps into the policyholder's position
Subrogation is the transfer of a claim from the injured party to whoever compensated them. Having paid, the insurer holds the right the policyholder had against the at-fault party.
The policy contract typically establishes this right explicitly and obliges the policyholder to cooperate with the recovery effort.
The arrangement exists so a loss ultimately rests with the party that caused it, rather than with the insurer of the party that suffered it.
It is why claims are paid before fault is settled
Determining fault can take months. Waiting for that determination before paying would leave policyholders without repairs or treatment in the interim.
Paying first and recovering later separates the two timelines. The policyholder is made whole promptly and the argument about responsibility proceeds afterward.
This is the practical reason to file with one's own insurer after an incident even when another party appears clearly responsible.
Deductibles are recovered proportionally
The policyholder's deductible was money they paid toward the loss, and it forms part of what the insurer seeks to recover.
Where recovery succeeds in full, the deductible is generally returned. Where it is partial, many arrangements share the recovered amount between insurer and policyholder.
Where fault is shared, recovery may be reduced by the policyholder's own share of responsibility, and the deductible refund shrinks accordingly.
Settling separately can defeat the claim
A policyholder who accepts a private payment from the at-fault party and signs a release may extinguish the very claim the insurer intended to pursue.
Policies commonly prohibit this, and doing it can affect the policyholder's own coverage for the loss as well as the recovery.
The same applies to health coverage, where a plan may have a claim against the proceeds of any personal injury settlement covering the same treatment.
The reason it takes so long to resolve
Recovery involves two insurers, sometimes an arbitration process between them, and occasionally litigation. None of that runs on the policyholder's timetable.
A deductible refund can therefore arrive many months after the repair, with no communication in the interval, and it is not a sign the claim was mishandled.
Because subrogation rights and the treatment of shared fault vary by state and by policy wording, how any specific case resolves is a matter for the insurer and, where relevant, an attorney.