A billing manager at a four-provider orthopedic practice counted one week what her team did with payer payments. Eleven paper checks arrived with paper explanations of benefits that had to be keyed line by line. Six payments arrived as virtual credit cards, each a single-use card number on a fax that someone typed into the terminal, paying a processing fee on every one. The rest came electronically and posted themselves. The electronic payers took about two hours of staff time for the week. The paper and card payers took nineteen.
ERA and EFT enrollment is the fix, and it is one of the few revenue cycle projects that pays for itself in the first month and then keeps paying. An electronic remittance advice (ERA) is the HIPAA-standard 835 transaction, a file that tells your practice management system exactly how each claim line was adjudicated. Electronic funds transfer (EFT) is the payment itself, deposited by ACH to your bank account with a trace number that links it to the 835. When both are in place, most payments post automatically, denials land in a work queue with their reason codes, and the money arrives days sooner than a check.
A glossary line: a CARC is a claim adjustment reason code (such as CO-45 for charges exceeding the contracted rate), and a RARC is a remittance advice remark code that adds detail. Both live in the 835 and drive automated posting and denial routing.
Key takeaways
- Health plans have been required to support the standard EFT and ERA transactions and operating rules since January 1, 2014; if a payer is still sending you paper, it is because you have not enrolled, not because the payer cannot.
- Enrollment is payer by payer, sometimes through the clearinghouse and sometimes directly, and usually needs a bank letter, a W-9 and an authorized signature.
- CMS guidance says a provider may request payment by ACH EFT and the plan must comply; virtual card payments and fee-bearing "premium" ACH tiers are optional, and the fees are avoidable.
- Auto-posting from the 835 is where the time savings come from, but it has to be configured: CARC-to-adjustment mappings, PLB handling and exception queues.
- Reconcile every 835 to a bank deposit using the TRN trace number, weekly, or unapplied cash will grow.
What the rules require
HIPAA named the 835 as the standard remittance transaction in 2000. The Affordable Care Act added operating rules, and the EFT and ERA operating rules developed by CAQH CORE took effect for health plans on January 1, 2014. Together they require plans to offer the standard EFT (an ACH CCD+ transaction carrying a trace number) and the 835, to reassociate the two with a matching TRN segment, and to use CARC and RARC combinations from a defined set for common business scenarios. Plans must also make enrollment reasonably available.
What the rules do not do is enroll you. Each payer has its own EFT and ERA enrollment process, and the default for a new provider or a new TIN is often paper. The work is administrative, not technical, and it is why this article is as much about a checklist as about technology.
How enrollment works, payer by payer
| Payer type | Where to enroll | What you will need | Typical time |
|---|---|---|---|
| Medicare Part B | EFT: form CMS-588 to your MAC. ERA: MAC EDI enrollment, often through your clearinghouse | Bank letter or voided check, PTAN and NPI, authorized official signature | 2 to 4 weeks |
| Medicaid fee-for-service | State Medicaid provider portal | Provider ID, bank information, W-9 | 2 to 6 weeks |
| Large national commercial payers (UnitedHealthcare, Aetna, Cigna, Humana) | Payer portal or the payer's payment vendor (for example Optum Pay, ECHO Health, Zelis, PaySpan, InstaMed); ERA often through the clearinghouse | TIN, NPI, bank information, portal administrator access | 1 to 4 weeks |
| Regional Blue plans | Plan portal or Availity for many plans | Same, plus provider number | 2 to 4 weeks |
| Small commercial plans and TPAs | Payer's own form, frequently paper or PDF; some pay only through a payment vendor | Same; expect a phone call to find the right form | Varies widely |
| Workers' compensation and auto | Often not enrolled; many still pay by paper | Ask each carrier; some use clearinghouse partners | Varies |
Two practical notes. First, ERA and EFT are separate enrollments with most payers, and finishing one does not finish the other. Practices routinely have EFT without ERA (money arrives, but posting is manual from a portal printout) or ERA without EFT (the file arrives, the check comes a week later, and reconciliation is a puzzle). Do both. Second, the clearinghouse can usually handle ERA enrollment for dozens of payers from a single dashboard, but EFT almost always needs the payer directly, because it involves your bank account.
The virtual card and fee problem
Over the past decade, several payers and their payment vendors shifted providers who had not enrolled in EFT to virtual credit cards: a single-use card number sent by fax or email, which the practice keys into its card terminal, paying its merchant processing fee (commonly 2 to 3.5 percent) on the payer's payment. Some vendors also offer a "premium" ACH tier with a percentage fee in exchange for faster funds or better reporting, alongside a free basic tier that is easy to miss.
CMS has stated in its HIPAA administrative simplification guidance that if a provider requests payment through the standard ACH EFT, the health plan must comply, and that a plan may not require a provider to accept a virtual card or a fee-bearing payment method. Enrolling in EFT is the request. If a payer or vendor continues to send virtual cards after enrollment, put the request in writing and cite the standard.
The arithmetic is not subtle. A practice that receives $600,000 a year in commercial payments by virtual card at an average 3 percent processing cost is paying $18,000 for the privilege of typing card numbers. Add the staff time, and the case for a week spent on enrollment forms makes itself.
What auto-posting actually does
Once the 835 arrives, the practice management system reads each claim line: billed, allowed, paid, patient responsibility, and the CARC and RARC codes explaining any difference. Configured well, the system posts the payment, posts the contractual adjustment (CO-45) automatically, transfers patient responsibility (PR-1 deductible, PR-2 coinsurance, PR-3 copay) to the patient balance, and routes anything else, denials and unusual adjustments, to a work queue. A biller who used to key 20 remits a day at six minutes each now reviews exceptions.
Configuration is where practices go wrong. Three settings matter. The CARC mapping decides which codes post as contractual adjustments and which stop for review; a system that auto-adjusts CO-97, CO-16 or CO-50 as if they were contractual will quietly write off denials forever. The PLB (provider-level adjustment) handling decides what happens to recoupments, interest and forwarding balances that are not tied to a single claim; these need a human. And the unmatched-claim rule decides what happens when the 835 references a claim the system cannot find, usually because of a corrected claim or a patient account merge.
Then reconciliation. Every 835 carries a TRN trace number and a payment amount; every EFT deposit carries the same trace number. Match them weekly. When the 835 total does not equal the deposit, something is in the PLB segment or a payment split across files. Practices that skip this step end up with unapplied cash that nobody can explain at year end. If your team wants an outside check on posting configuration and unapplied balances, that is part of our RCM audit, and day-to-day posting is part of our medical billing service.
Questions we hear
We get ERAs through the clearinghouse but the payer still mails checks. Why?
Because EFT enrollment is separate and goes to the payer or its payment vendor, not the clearinghouse. Find the payer's EFT form, complete it with a bank letter, and confirm the effective date. Until then, match each mailed check to its ERA by claim numbers and amounts rather than re-keying.
Is it safe to give every payer our bank account details?
EFT enrollment requires it, and it is the same information on every check you deposit. The risk to manage is fraudulent enrollment changes: a criminal submits a form redirecting your payments to a different account. Ask each payer what verification it performs on account changes, make sure the contact on file is a practice-controlled email, and watch for a payer that stops paying.
Can we auto-post everything and review nothing?
No. Auto-post payments, contractual adjustments and patient responsibility transfers. Stop for denials, PLB adjustments, unmatched claims, and any payment that differs from the expected allowed amount by more than a threshold you set. The exception queue is where underpayments are found.
What to do this week
- List every payer that paid you last month, mark whether each is ERA, EFT, both or neither, and total the dollars in the "neither" and "virtual card" columns.
- Start EFT enrollment with the three largest payers not yet on ACH, beginning with CMS-588 for Medicare if that is one of them.
- Ask the clearinghouse to run ERA enrollment for every payer it supports that is not yet sending 835 files.
- Send a written ACH EFT request to any payer or vendor still sending virtual cards, and switch any "premium" tier to the free basic tier.
- Review the CARC auto-adjust mapping in your practice management system and remove any denial codes from the automatic contractual list.
- Set a weekly 835-to-deposit reconciliation using TRN trace numbers and assign an owner.
