What Is EDI 270/271 and How Does Eligibility Verification Work?
If your front desk staff is calling payers to verify patient insurance coverage, you’re leaving time and money on the table. EDI 270 and 271 transactions are the industry-standard way to do this electronically — fast, accurate, and at scale.
Here’s how they work.
What Is an EDI 270?
An EDI 270 is an Eligibility and Benefit Inquiry transaction. It’s the message your system sends to a payer (or clearinghouse) to ask: “Is this patient covered? What are their benefits?”
A 270 typically includes:
- Subscriber information — member ID, name, date of birth
- Provider information — NPI, name, tax ID
- Date of service — when the inquiry is for
- Service type — what type of benefit you’re asking about (medical, dental, pharmacy, etc.)
The 270 is essentially a structured question. The payer receives it, looks up the member, and sends back an answer — the 271.
What Is an EDI 271?
The EDI 271 is the Eligibility and Benefit Response. It’s the payer’s answer to your 270 inquiry.
A 271 can tell you:
- Whether the patient is active or inactive
- Deductible amounts and how much has been met
- Copay and coinsurance by service type
- Out-of-pocket maximums
- Plan limitations — visit limits, prior auth requirements
- Coordination of benefits — if the patient has multiple payers
The 271 can be simple (active/inactive with basic plan info) or extremely detailed depending on the payer. Some payers return dozens of benefit segments; others return the bare minimum. You’ll learn quickly which payers are verbose and which are not.
The 270/271 Transaction Flow
Here’s how a typical eligibility check works end-to-end:
- Patient schedules an appointment — your system triggers an eligibility inquiry
- Your system generates a 270 — formatted per HIPAA X12 5010 standards
- 270 is sent to the payer — directly or via a clearinghouse
- Payer processes the inquiry and generates a 271 response
- 271 is returned — usually in seconds for real-time, or batched overnight
- Your system parses the 271 — populates eligibility data in your EHR or PM system
Real-time eligibility checks (synchronous 270/271) are now common. Most major payers support responses in under 5 seconds via clearinghouse connections.
Key Segments in a 270 File
EDI files are structured using loops and segments. Here are the most important ones in a 270:
| Segment | Purpose |
|---|---|
| ISA / GS | Interchange and functional group headers (envelope) |
| ST | Transaction set header |
| BHT | Beginning of Hierarchical Transaction — sets the purpose (inquiry) |
| HL (20) | Information Source level — identifies the payer |
| HL (21) | Information Receiver level — identifies the submitter |
| HL (22) | Subscriber level — patient/member info |
| EQ | Eligibility or Benefit Inquiry — what you’re asking about |
| SE / GE / IEA | Transaction, group, and interchange trailers |
The EQ segment is where you specify what benefit type you’re inquiring about. Service type codes like 30 (health benefit plan coverage) or 35 (dental care) tell the payer exactly what to return.
Key Segments in a 271 File
The 271 response mirrors the 270 structure but adds benefit detail segments:
| Segment | Purpose |
|---|---|
| EB | Eligibility or Benefit Information — the core data |
| MSG | Free-form message from the payer |
| LS / LE | Additional information loops |
| AAA | Request validation — indicates errors or rejections |
The EB segment is the workhorse of the 271. Each EB loop describes a specific benefit — coverage status, deductible, copay, etc. A single 271 can contain dozens of EB segments for a complex plan.
Common 271 Response Codes
The first element of the EB segment tells you the coverage status:
| Code | Meaning |
|---|---|
| 1 | Active coverage |
| 6 | Inactive |
| 7 | Terminated |
| A | Co-insurance |
| B | Co-payment |
| C | Deductible |
| R | Deductible: Out-of-Pocket |
Understanding these codes is essential for interpreting what a payer sends back — especially when a plan has multiple active benefit types.
Real-Time vs. Batch Eligibility
Real-time (synchronous): Send a 270, get a 271 back in seconds. Best for point-of-service verification at check-in. Most clearinghouses support this for major payers.
Batch (asynchronous): Submit a file of 270s overnight, receive a batch of 271s the next morning. Useful for verifying a full schedule the night before — or for payers that don’t support real-time.
Many practices run both: batch checks the night before for the next day’s appointments, and real-time catches same-day adds or insurance changes at check-in.
Why Eligibility Verification Fails
Even with 270/271 in place, eligibility checks go wrong. Common causes:
- Member ID mismatch — patient gave you an old card; payer can’t find the record
- Name/DOB mismatch — even small discrepancies (Jr., hyphenated names) cause lookup failures
- Payer doesn’t support real-time — you get a rejection or have to call
- Plan not yet active — new insurance effective date is in the future
- Coordination of benefits not updated — payer shows secondary when it’s now primary
When a 271 comes back with an AAA segment, it means the inquiry was rejected or couldn’t be processed — not that the patient is ineligible. Check the error code before assuming coverage issues.
How to Read a 270/271 File
270 and 271 files look like most EDI — a wall of segments separated by tildes, with asterisks as delimiters. Not exactly readable at a glance.
ISA*00* *00* *ZZ*SENDER *ZZ*RECEIVER *260417*1200*^*00501*000000001*0*P*:~
GS*HS*SENDER*RECEIVER*20260417*1200*1*X*005010X279A1~
ST*270*0001*005010X279A1~
BHT*0022*13*10001234*20260417*1200~
HL*1**20*1~
NM1*PR*2*BLUE CROSS BLUE SHIELD*****PI*12345~
HL*2*1*21*1~
NM1*1P*2*GENERAL HOSPITAL*****XX*1234567890~
HL*3*2*22*0~
NM1*IL*1*SMITH*JANE****MI*ABC123456789~
DMG*D8*19800101*F~
EQ*30~
SE*10*0001~
GE*1*1~
IEA*1*000000001~To read this without going cross-eyed, paste it into EDI Paisan — it parses and displays the structure in a readable format, highlights each loop and segment, and works on files up to 100MB. No install, no upload to a server.
The Bottom Line
EDI 270/271 is the backbone of eligibility verification in U.S. healthcare. If you’re processing claims, you’re almost certainly using it — or should be. Understanding the transaction structure helps you diagnose failures faster, build better integrations, and stop relying on phone calls to verify coverage.
Need to inspect a 270 or 271 file? Try it free at edipaisan.com.