Cesara checks hospital payments against contracts and prepares the appeal

A hospital can receive a payment and still be owed money. Cesara is building AI agents to identify that gap by comparing claims with payer contracts, then assembling appeals that cite the clause behind the missing reimbursement.

The company’s launch describes a system that starts before the payment arrives. It reads contract terms, calculates the expected reimbursement when a claim is submitted and checks the eventual payment against that amount. The aim is to catch discrepancies earlier than a retrospective spreadsheet review.

Cesara gives an illustrative example: a payer sends $42,000, but a stop-loss provision means the claim should receive $78,000. Its software is designed to show the difference with the relevant contract language attached. The example explains the workflow; it is not presented as a disclosed customer recovery.

Watch Cesara’s original launch demonstration.

The underlying challenge is keeping the calculation current. Contracts accumulate amendments, rate increases, fee schedules and exceptions. A system checking payments needs those changing terms to match the version that applies to a particular claim, not simply the original agreement.

Cesara says it extracts rates, carve-outs, stop-loss provisions and scheduled increases from contracts. It connects that information with systems including Epic, contract-management software, SharePoint and payer email. The launch also names Waystar and Availity among its connections.

When it identifies an underpayment, the product can prepare an appeal containing the contract excerpt and the payer’s electronic remittance, known as an 835. Cesara says it tracks the appeal through recovery and closure. The source-linked evidence is central to the pitch: a team should be able to see why the software believes money is owed.

Automation is intended to arrive in stages. First, the system runs alongside an organization’s existing process so staff can assess accuracy on their own claims. It then recommends actions for approval. Only after those steps does it move to automatic recovery within limits set by the customer.

Cases above an approval threshold still go to the health system’s team. Cesara says actions are logged and linked to their supporting contract language. That phased design matters because a questionable interpretation shouldn’t silently become an appeal sent on a hospital’s behalf.

The platform also lets teams ask questions about contracts in ordinary language and model proposed reimbursement rates before negotiations. That extends the same organized contract information from payment review into preparation for future payer discussions.

Co-founders Xinan Rahman and Junwoo Lee are building Cesara in Y Combinator’s Fall 2026 batch. Rahman previously founded enterprise-software implementation startup Auctor. Cesara’s public launch does not disclose customer counts, recovered revenue or independently measured accuracy, so the scale of its deployment remains unclear.

Its official website includes endorsements describing the burden of manually connecting contract amendments and payment records. Those statements reinforce the problem the company is pursuing, while leaving the product’s performance to be established in each organization’s own workflow.

Cesara is offering prospective customers a claims audit. For a revenue-cycle team, the first useful result would be a concrete discrepancy it can inspect: the submitted claim, the payment received and the contract provision explaining the difference.

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