How pet insurance reimbursement works depends on a basis most buyers never ask about: how the policy decides the eligible amount before it applies your reimbursement percentage. There are three bases in the US market, actual-cost, a benefit schedule, and usual-and-customary, and they can turn the same vet bill and the same advertised percentage into very different payouts. Two policies that both say "80% reimbursement" can pay back materially different amounts if one reimburses 80% of the actual bill and the other reimburses 80% of a scheduled allowance. This page explains the three models. The percentage itself, the 70/80/90 choice, is broken down on the reimbursement percentage explained guide.
The reimbursement basis
Before a policy applies your reimbursement percentage, it decides the eligible amount, and that decision is the reimbursement basis. The eligible amount is not always the full bill. Some policies start from the actual cost you paid, some start from a fixed allowance set by a benefit schedule, and some start from what the policy considers a usual-and-customary charge for that service in your area. The percentage then runs against the eligible amount, not the raw bill, so the basis quietly sets the ceiling on what any percentage can return.
This is the part of reimbursement that the headline number hides. A buyer comparing two policies on the reimbursement percentage alone is comparing the last step of the calculation while ignoring the step that differs. The four-step calculation, eligible amount minus deductible, times reimbursement percentage, capped at the annual limit, is laid out on the how pet insurance works guide; this page zooms in on how the eligible amount is set in the first place.
The three models
The actual-cost model is the most common at the major reviewed carriers and the most generous. It starts from the real amount you paid the clinic, subtracts the deductible, and reimburses the chosen percentage of the remainder, with no separate schedule trimming the bill first. Lemonade describes exactly this flow: you pay the treatment cost, the claim is approved, the deductible is subtracted, and the coinsurance percentage is applied to the remainder [Lemonade: The Ultimate Lemonade Pet FAQ, 2026]. Because the basis is the actual bill, the only haircuts are the deductible and the percentage you selected.
The benefit-schedule model sets a fixed dollar allowance per service, and reimburses against the allowance rather than the bill. If the schedule allows a smaller amount than the clinic charged, the reimbursement is calculated on the smaller number even at a high percentage, so the buyer absorbs the gap. The usual-and-customary model is a softer version of the same idea: the policy caps the eligible amount at what it considers a reasonable charge for the service in your region, and reimburses the percentage of that capped amount. Trupanion's coverage documentation contrasts paying on actual veterinary costs against schedule-based approaches that pay on a predetermined allowance [Trupanion: How pet insurance deductibles work, 2026].
Actual cost: the eligible amount is the real bill you paid; only the deductible and your reimbursement percentage reduce it. Benefit schedule: a fixed allowance per service sets the eligible amount, so a bill above the allowance is reimbursed against the smaller scheduled number. Usual-and-customary: the eligible amount is capped at what the policy considers a reasonable regional charge, then the percentage applies. The NAIC Pet Insurance Model Act requires the policy to disclose its reimbursement basis and any benefit schedule so a buyer can see which model applies [NAIC: NAIC Passes Pet Insurance Model Act, 2022].
Why the model changes the payout
The model decides the eligible amount, and the eligible amount sets the ceiling that the percentage can never beat. On an actual-cost policy, a high reimbursement percentage returns a high share of the real bill. On a benefit-schedule policy, the same percentage returns a high share of an allowance that may sit below the real bill, so the effective reimbursement on the bill is lower than the advertised percentage suggests. This is why two quotes that both say 80% are not comparable until you know each one's basis, and it is the single most common reason a claim pays back less than a buyer expected.
The practical danger is in the comparison, not the math. Benefit-schedule and usual-and-customary policies often advertise the same percentages as actual-cost policies, and sometimes a lower premium, because the schedule caps the carrier's exposure. Pets Best documents reimbursement on eligible covered costs and lays out the terms a buyer should read to confirm the basis rather than infer it from the percentage [Pets Best: What Does Pet Insurance Cover and Not Cover?, 2026]. A buyer who only compares percentages can pick the worse policy thinking it is equal.
How to check which model a quote uses
Read the policy for the words that name the basis: actual cost or actual veterinary expenses points to the most generous model, while benefit schedule, allowance, or usual-and-customary signals a capped eligible amount. If a quote will not state the basis plainly, treat that as the answer and assume a schedule until proven otherwise. Normalizing the reimbursement basis across quotes is one of the variables the how to compare pet insurance quotes guide walks through, and the percentage that runs against the basis is on the reimbursement percentage explained guide. Confirm the model before the price; the model decides how much of any bill comes back. Every provider is read the same way against the published methodology.