A public adjuster's fee is almost always a contingency fee, meaning a percentage of what the insurance company actually pays you on the claim, not a percentage of your home's value, not a percentage of the repair estimate, and not a flat cut of whatever the insurer originally offered before you hired help. If the claim pays nothing, in most states the adjuster is owed nothing. That single structural fact is the whole point: it puts your public adjuster's financial interest on the same side of the table as yours, instead of on the insurer's payroll like the adjuster the insurance company sends out.
What "percentage of the claim payment" actually means
The percentage in a public adjuster's contract applies to the total amount the insurer pays on the claim, whatever that number turns out to be, not to a number fixed in advance. If your roof claim is initially valued by the insurer at a modest figure, and your public adjuster documents additional damage and negotiates the payment up, the fee is calculated on the final, higher number, not the insurer's first offer. That is exactly why the incentive is aligned: the adjuster only gets more if you get more.
Fee percentages vary by state, by the size and complexity of the claim, and sometimes by whether the loss falls under a declared disaster. Florida, for example, caps the contingency fee by statute at 10% of the claim payment for the first year following a Governor-declared state of emergency, and 20% for property claims outside that window. Not every state has a hard statutory cap, so read your specific contract's percentage line rather than assuming a number.
Supplemental payments and the fee
Property claims rarely close with a single check. It is common for an insurer to issue an initial payment, and then for a public adjuster to go back with additional documentation, a revised estimate, or engineering support and win a supplemental payment weeks or months later. In a standard contingency-fee public adjuster contract, the fee percentage applies to the full recovery, meaning the original payment plus any supplements, not just to the first check. That is a normal and expected structure in this industry, but you should confirm in writing that your contract describes the fee this way so there is no dispute later about what counts as "the claim payment."
Contingency versus flat-fee and hourly models
The contingency model is the default nationwide, but it is not universal. Louisiana is the outlier: state law prohibits public adjusters there from charging any fee that is contingent on, or calculated as a percentage of, the claim payment. Louisiana public adjusters instead charge a flat fee or an hourly rate. If you are working a Louisiana claim, expect a different kind of engagement letter than the contingency contract used almost everywhere else, and expect to negotiate the flat amount or hourly rate up front rather than a percentage.