We audited a four-provider pediatric practice whose denial rate looked fine until we sorted the remittances by reason code. CO-27 (expenses incurred after coverage terminated), CO-22 (care may be covered by another payer) and CO-31 (patient cannot be identified as our insured) together made up almost 40 percent of the denials by count. None of them was a coding problem. Every one of them was known, or knowable, before the child walked in. The practice ran eligibility at check-in, on the day of the visit, by glancing at a green check mark in the practice management system. Green meant "the payer answered", not "the patient is covered for this service with this provider today".

That is why this checklist exists. Eligibility verification is the one revenue cycle step that is fully under the practice's control, happens before any cost is incurred, and takes a couple of minutes per patient when it is done in batch two or three days ahead. Done right, it removes most registration denials, gives the front desk a real number to collect at the visit, and catches the coordination of benefits problems that otherwise surface 45 days later as a denial.

Verification done right means confirming five things before the visit, not one: that coverage is active on the date of service, which plan and network the patient is in and whether your provider is in it, what the benefit is for the specific service scheduled, what the patient will owe (deductible remaining, copay, coinsurance), and whether another payer should be billed first. Each group below is a checklist you can hand to the person who does this work, with the field or screen to look at and the mistake it prevents.

When to verify, and with which tools

Verify in a batch 48 to 72 hours before the appointment, so there is time to call the patient about a terminated plan or a missing referral. Re-verify on the day of service for anything high-dollar, for Medicaid patients (Medicaid eligibility can change month to month, and in some states, day to day) and for anyone whose first check returned an inactive, pended or ambiguous result. New patients and patients who report a job change, a new card or a birthday that moved them onto Medicare get a phone call to the payer, not just an electronic check.

The electronic check is the HIPAA 270/271 eligibility inquiry and response, which your practice management system or clearinghouse sends to the payer. For Medicare, the same transaction runs through the HIPAA Eligibility Transaction System (HETS), either directly or through your clearinghouse, and returns real-time Part A and B entitlement, Medicare Advantage and Part D enrollment, Medicare Secondary Payer records, deductible status and preventive service dates. The CAQH CORE operating rules adopted by CMS require payers to return specified patient financial responsibility data (deductible, copay, coinsurance) in the 271 for a set of common service type codes and to respond in real time within seconds, so the data is there if your system displays it. Payer portals fill the gaps for benefits the 271 does not carry, such as visit limits or network tier details, and the phone is the last resort, with the reference number written down every time.

Checklist 1: identity and active coverage

  • Card on file is current. Scan both sides of the card at every visit where the patient says anything changed, and at least annually. Compare the member ID on the card with the one in the system character by character; transposed digits cause CO-31.
  • Name, date of birth and sex match the payer's record. The 271 returns the subscriber and dependent names as the payer holds them. A hyphenated surname, a nickname or a legal name change is enough to reject a claim at the clearinghouse.
  • Subscriber versus patient. Record the subscriber's name, date of birth and relationship when the patient is a dependent. Claims for a child or spouse need the subscriber information in the right loop (2000B and 2000C on the 837P, boxes 4 and 7 on the CMS-1500).
  • Coverage is active on the date of service. Read the eligibility dates, not just the status. A plan that is active today and terminates at the end of the month will deny a visit scheduled next month with CO-27. Look for a termination date and a plan begin date, and check that neither falls between now and the appointment.
  • Payer ID and claims address. The card lists a payer ID for electronic claims and a mailing address. Plans administered by a third-party administrator or routed through a repricer often have a payer ID that is not the brand on the front of the card. Confirm the payer ID in the system is the one on the card.
  • Medicaid: eligibility for this month. Confirm the aid category and the managed care plan assignment for the month of service. A patient who was in one Medicaid managed care organization last month may be in another now, and the fee-for-service program will not pay a claim that belongs to a plan.

Checklist 2: plan type, network and referrals

  • Product type. HMO, PPO, EPO, POS, high-deductible plan with a health savings account, Medicare Advantage, Medicaid managed care, Marketplace tier. The product decides whether referrals and primary care assignment matter and how large the deductible is likely to be.
  • Your provider is in network for this product. Being contracted with a payer does not mean being in network for every one of its products. Narrow-network Marketplace and Medicare Advantage plans are the usual surprise. Check the payer's directory or portal for the rendering provider and the service location.
  • Primary care physician assignment. For HMO and most Medicaid managed care plans, the 271 or the portal shows the assigned PCP. If a new patient wants your practice to be their PCP, the assignment has to change with the plan before the visit or the claim will deny.
  • Referral on file. HMO specialists need a referral from the assigned PCP, with the referral number, the number of visits authorized and the date range. Verify it in the payer system; a paper referral in the patient's hand means nothing if the PCP's office never submitted it.
  • Prior authorization required. Check the scheduled service against the payer's authorization list and, if required, confirm the authorization exists before the visit. Eligibility and authorization are separate processes, and the eligibility screen will not tell you an authorization is missing.
  • Plan year and accumulators. Note the plan year start date. Deductibles and visit limits reset then, which is why January and the month a new employer plan starts are the heaviest months for patient balances.

Checklist 3: the benefit for the service being scheduled

  • Request the right service type code. A generic eligibility check uses service type code 30 (health benefit plan coverage) and returns general coverage. For the actual visit, request the specific service type: 98 for a professional office visit, 50 for outpatient hospital, 33 for chiropractic, MH for mental health, UC for urgent care, AL for vision, 88 for pharmacy. The payer is required to return the financial responsibility for these specific types, and the copay for a specialist visit is often different from the one for primary care.
  • Covered, excluded or limited. Some benefits are simply excluded (routine foot care, many hearing and vision services, cosmetic procedures), and some are limited by visit count or dollar amount (physical therapy, chiropractic, behavioral health in some older plans). Record the limit and the number used to date.
  • Preventive versus diagnostic. A wellness visit, screening colonoscopy or screening mammogram is often covered without cost sharing, while the same service coded as diagnostic carries the deductible. Confirm how the payer will treat the visit as it is actually scheduled, and tell the patient if a finding during a screening can change the cost.
  • Telehealth benefit. If the visit is virtual, verify that telehealth is covered for the service, whether audio-only qualifies, and what the cost sharing is; many plans treat it differently from in-person care and the rules change with plan years.
  • Frequency rules. For Medicare preventive services, HETS returns the next eligible date for services such as the annual wellness visit (G0439), screening mammography and colorectal screening. Scheduling before that date produces a denial the patient will be asked to pay.
  • Medical necessity and coverage policies. Eligibility tells you the benefit exists. Whether a specific diagnosis is covered for a specific procedure is a coverage policy question (LCDs and NCDs for Medicare, medical policies for commercial plans) and belongs to the authorization and coding steps, not this one. Note it, do not skip it.

Checklist 4: patient financial responsibility

  • Deductible: total and remaining. The 271 returns the individual and family deductible amounts and, for most payers, the remaining balance. Use the remaining balance and the date it was calculated; a claim from another provider may post tomorrow.
  • Copay for this service type. Specialist, primary care, urgent care and preventive copays differ. Read the one that matches the scheduled visit.
  • Coinsurance percentage. After the deductible, the patient owes a percentage of the allowed amount, not of the charge. To estimate it, you need the contracted allowed amount for the expected CPT code; our contract rate benchmark helps when the fee schedule is not loaded in the system.
  • Out-of-pocket maximum: remaining. Once the patient has met it, cost sharing stops. Patients in the second half of a plan year with a serious illness are often there, and collecting a copay they do not owe is a refund you will have to process later.
  • Write the estimate down and tell the patient. A pre-visit call or text that says "your plan shows $1,200 of deductible remaining; the estimated cost for your visit is $185, due at the visit" doubles as consent to collect. For uninsured and self-pay patients, the federal No Surprises Act good faith estimate rules apply and the estimate needs to be in writing on the required timeline.
  • Medicare Part B specifics. The Part B deductible changes every January; CMS announces it each fall and HETS returns the remaining amount. Coinsurance is 20 percent of the Medicare-approved amount for most Part B services, with no annual out-of-pocket maximum unless the patient has supplemental coverage. If the patient has a Medigap plan, record it; it is billed after Medicare, often automatically by crossover.

Checklist 5: other coverage and coordination of benefits

  • Ask the question every time. "Do you have any other insurance, including through a spouse, a parent, a job, Medicare or Medicaid, or related to an accident or workers' compensation?" is the question that prevents CO-22. Put it on the intake form and ask it aloud.
  • Determine the order. Commercial plans follow coordination rules in the plan documents and state law (the birthday rule for dependent children, active employee coverage before retiree coverage). Medicare is secondary to a current employer's group health plan when the employer has 20 or more employees for age-based entitlement, and to liability, no-fault and workers' compensation coverage for related injuries. Medicaid is almost always the payer of last resort.
  • Check the Medicare Secondary Payer record. HETS returns MSP occurrences with the other insurer and the dates. If Medicare's record says a group health plan is primary and the patient says that job ended two years ago, the patient (or you on their behalf) needs to call the Benefits Coordination & Recovery Center to update it before the claim will pay.
  • Medicare Advantage replaces Original Medicare for billing. If the 271 shows an MA plan, the claim goes to the plan, not to the Medicare Administrative Contractor. Patients often hand over the red, white and blue card out of habit. Ask for the plan card.
  • Dual eligibles. A patient with Medicare and Medicaid may be in a Qualified Medicare Beneficiary program, in which case federal law prohibits billing the patient for Medicare cost sharing. Confirm the Medicaid category and flag the account so the front desk does not collect a copay.
  • Accident and injury claims. If the visit relates to an accident, collect the date of injury, the liability or auto carrier and the claim number. Health plans will deny or pend these until the other carrier has responded.

Checklist 6: record the result so a denial can be fought

  • Save the 271 or portal screen. Most systems attach the eligibility response to the encounter. If yours does not, save a dated screenshot or print to the chart. A payer that denies CO-27 after returning active coverage on the date of service will reprocess when you send its own response back.
  • Record the reference number and representative name for phone verifications. Date, time, name, reference number. This is the evidence for a "we were told it was covered" appeal, and without it the appeal is a story.
  • Flag exceptions for follow-up. Inactive coverage, missing referral, authorization required, other coverage reported, estimate above a threshold. Each flag goes to a named person with a deadline before the visit.
  • Tell the front desk what to collect. The check-in screen should show the copay or estimate as a number, with a note on why. "Collect $40 copay; deductible met; QMB, do not collect" is what a well-run system shows.

Printable summary table

CheckWhere to lookWhat a good result looks likeDenial it prevents
Member ID, name, DOB matchCard scan vs 271 subscriber/dependent segmentExact match, including suffixes and hyphensCO-31, clearinghouse rejection
Active on date of service271 eligibility begin and end datesBegin date before DOS, no end date before DOSCO-26, CO-27
Correct payer IDCard back, clearinghouse payer listPayer ID in system equals cardCO-109, misrouted claim
Product and network271 plan description, payer directoryProvider and location listed in network for this productOut-of-network processing, CO-242
PCP and referral271 PCP segment, payer portal referral screenYour practice assigned, or referral number with visits and datesCO-183, CO-288
AuthorizationPayer authorization list, portalAuthorization number, codes, units and dates recordedCO-197, CO-15
Benefit for service271 with specific service type code, portalCovered, limits noted, preventive vs diagnostic confirmedCO-96, CO-204, CO-119
Deductible, copay, coinsurance, OOP271 financial responsibility segmentsRemaining amounts with as-of date; estimate writtenUncollected balances, refunds
Other coverage and orderIntake question, HETS MSP record, payer COB screenPrimary and secondary identified; MSP record currentCO-22, OA-23 confusion, CO-109
Medicare Advantage vs OriginalHETS plan enrollment segment, plan cardClaim routed to the plan with the correct payer IDCO-109
Medicare preventive frequencyHETS next eligible dateScheduled on or after the eligible dateCO-119, patient balance
QMB or other dual statusMedicaid eligibility, HETSAccount flagged "do not collect cost sharing"Improper patient billing
Evidence savedEncounter attachments, call log271 or screenshot plus reference numberLost appeal

Practices that run this list in batch, two days ahead, usually find that the eligibility portion of their denials shrinks to the cases where the payer's own data was wrong. If you want someone to look at where your registration denials actually come from, our RCM audit starts with exactly this sort by reason code.

Questions we hear

How far in advance should we verify eligibility?

Two to three business days before the visit for the batch check, so there is time to reach the patient, and again on the day of service for high-dollar procedures, Medicaid patients and anyone whose first result was not clean. Verifying weeks ahead is not useful because coverage changes; verifying only at check-in is too late to do anything about what you find.

The eligibility check said active but the claim denied for terminated coverage. What happened?

Usually one of three things. The check was run before a retroactive termination was posted (common when an employer reports a job loss late). The check confirmed the payer but not the product, and the patient had moved to a different plan under the same brand. Or the date of service fell after a termination date that was in the response but nobody read. Send the payer its own 271 with the appeal; if the termination was retroactive, the claim becomes a patient balance or, where the patient had other coverage, a claim to the other payer, and timely filing from the date you learned of it usually applies.

Do we need to verify every patient at every visit?

Yes for the active coverage and copay check, because it is fast and automated. The deeper benefit and coordination checks can be reserved for new patients, patients with a reported change, high-dollar services, and a periodic refresh (many practices do it at the first visit of each plan year). Medicaid patients should be verified monthly at minimum.

Can we collect the deductible before the visit?

You can collect an estimate for in-network care if your payer contracts allow it, and most do, but the amount is not final until the claim adjudicates because another provider's claim may post first. Tell the patient it is an estimate, reconcile after the remittance, and refund promptly when you collected too much. Some payer contracts and state laws restrict pre-service collection beyond the copay, so check both before changing your policy.

What is the difference between eligibility and benefits?

Eligibility answers whether the patient has active coverage with this payer on this date. Benefits answer what that coverage pays for the specific service: covered or not, limits, cost sharing, network rules. A 270 request with the generic service type code gives you eligibility and headline benefits; the specific service type codes and the portal give you the benefit detail. Most "eligibility denials" are really benefit problems that an eligibility check alone could not have caught.

Who should do eligibility verification?

Someone whose job it is, with a daily list and a quiet hour. In small practices that is often the front desk lead working from the schedule two days out; in larger practices it is a dedicated verification specialist or an outsourced team. The person who does it should also see the eligibility denials from the remittances, because that feedback is how the checklist improves.

Sources and references