Four common reasons: the deductible or out-of-pocket accumulator moved between the estimate and the visit as other claims processed; services were added or changed during the visit; the estimate used plan-level rather than CPT-level benefits; or the fee schedule used did not match the payer's contracted rate. The first is unavoidable and small; the last two are process failures.
Patients notice the gap. In careviso's April 2025 survey of 2,500 patients, 63% said they were billed more than their initial estimate. The fix is not to stop estimating; it is to verify closer to the visit, at the CPT level, with the right fee schedule, and to tell the patient what the estimate does and does not include.
