What is eligibility verification in medical billing?

Payers and coverage

What is Eligibility Verification?

Also called: insurance verification · benefits verification · 270/271

Eligibility verification confirms a patient's active coverage, benefits, deductible status, copay, coinsurance and authorization requirements before the service is delivered. It runs electronically through the X12 270 inquiry and 271 response, and it prevents the largest single category of denials.

Optum attributes 24.3% of denials to registration and eligibility errors — the largest denial category there is, and the one with the cheapest fix.

Verifying that coverage is active is only half of it. The response also carries the deductible remaining, which determines what to collect at the desk, and plan-level authorization requirements, which determine whether the visit should proceed at all.

Where Vizora handles this

Eligibility verification

Primary sources

Where "Eligibility Verification" is defined by the bodies that set the rules, rather than by us.

CAQH Index: cost of administrative transactions (opens in a new tab)
CAQH — Per-transaction cost of eligibility checks, claim status inquiries and prior authorization, manual versus electronic. The best public evidence for automating front-end work.
Medicare Secondary Payer Manual (opens in a new tab)
Centers for Medicare & Medicaid Services — When Medicare pays second, and to whom the claim goes first. Coordination-of-benefits denials are resolved here rather than with the patient.

Last reviewed August 20, 2026

Related terms

Prior Authorization

Prior authorization is a payer requirement that a service be approved before it is delivered. Without it, the claim is denied regardless of medical necessity, and in most contracts the balance cannot be billed to the patient — the practice absorbs it entirely.

Coordination of Benefits

Coordination of benefits determines which payer is primary when a patient has more than one plan, and in what order the others pay. Billing the wrong payer first produces a denial that cannot be fixed by resubmission alone — the payers' own COB records must be corrected first.

Denial

A denial is a claim the payer adjudicated and refused to pay. It differs from a rejection, which never entered adjudication. That distinction determines your remedy: a rejected claim is corrected and resubmitted, while a denied claim must be appealed within the payer's deadline.

Patient Responsibility

Patient responsibility is the portion of an allowed amount the patient owes: copay, coinsurance, deductible and non-covered charges. It is identified on the remittance by PR group codes, and it has become materially harder to collect as high-deductible plans have grown.

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