270 outbound — composing a request

Outcome

A 270 eligibility-inquiry transaction goes out cleanly to the right partner, the request asks for exactly the benefit information you need (no more, no less), and the response is correlated back to the originating member + service date.

Prerequisites

Scope	What it lets you do
edi.transaction.read	View transactions
edi.eligibility.run	Originate 270s through the gateway

A trading partner with 270 outbound and 271 inbound capabilities (see 2.4 — Capabilities). A registered member with at least one active coverage policy on the date of inquiry.

270 anatomy

Source: packages/x12/src/outbound/eligibility-270.ts. Implementation convention: 005010X279A1.

ISA → GS → ST*270 → BHT
  Loop 2000A — Information Source (the payer)
    HL*1**20*1
    NM1*PR (payer)
  Loop 2000B — Information Receiver (the provider / submitter)
    HL*2*1*21*1
    NM1*1P (provider)
  Loop 2000C — Subscriber
    HL*3*2*22*1
    NM1*IL (subscriber)
    DMG (DOB / gender)
    DTP (eligibility date)
  Loop 2000D — Dependent (optional)
    HL*4*3*23*0
    NM1*03 (dependent)
  Loop 2110C — Eligibility / Benefit Inquiry
    EQ (service type code)
SE → GE → IEA

Service-type codes

The most consequential element is EQ01 — the service type code. Choosing well makes the 271 response useful; choosing poorly produces either too little detail or a payer-side rejection.

Code	Meaning	When to use
30	Health Benefit Plan Coverage	Default — generic "is this person eligible". Returns active/inactive plus minimal cost-share.
R	Returns full benefit info	Some payers honor this; others reject as too broad.
1	Medical Care	Outpatient medical services.
35	Dental Care
47	Hospital	Inpatient.
48	Hospital — Inpatient	Specific to admission planning.
49	Hospital — Outpatient
54	Long Term Care
86	Emergency Services
88	Pharmacy
98	Professional (Physician) Visit — Office	Office visit.
BU	Psychiatric — Outpatient	Mental health outpatient.
BV	Psychiatric — Inpatient
MH	Mental Health	Generic mental-health bucket — partner-specific.

When a single 270 needs multiple service types, repeat the EQ segment inside loop 2110C. Most partners support up to 99 repeats.

Steps

1. Trigger an eligibility request through the rcm-app /eligibility page (real-time check) or via a batch sweep. Either flow funnels through the same gateway code path.

2. The gateway composes the 270:

   • Resolves the trading partner from the routing rule for 270 / payer / state.
   • Allocates an ISA / GS / ST control number triple from the control-number-manager.
   • Composes the 2000A through 2110C loops from the member record and the requested service date.
   • Applies any companion guide bound to 270 for this partner.
   • Submits via the partner's transport.

3. The transaction record appears at /transactions with tx_type = 270, direction outbound, status submitted. Click in to see the segment trace.

4. Wait for the 271 (typically seconds for real-time, minutes for batch). The 271 arrives as a separate inbound transaction with correlation_id pointing back at the 270's transaction ID.

Reading the segment trace

/transactions/:id opens the segment trace. The 270 trace shows:

Section	Notable elements
ISA	Receiver ID, control number, usageIndicator (P or T).
GS	HS functional code, our submitter, 005010X279A1.
BHT	BHT02 = 13 (request); BHT06 = RT realtime.
2000A NM1*PR	Payer name + ID.
2000B NM1*1P	Provider NPI.
2000C NM1*IL	Subscriber name + member ID.
2000C DMG	DOB + gender — required for matching.
2000C DTP	The service date the inquiry covers.
2110C EQ	Service type code(s).

Anything missing from this list is the gateway's responsibility — file an issue if the trace shows a malformed segment.

Common variations

Patient who is not the subscriber

Add the dependent loop 2000D with NM1*03. The 270 then asks the payer to look the dependent up under the subscriber's policy.

Multi-service type request

Repeat EQ inside 2110C:

EQ*30~
EQ*47~
EQ*BU~

Returns one EB per service type in the 271.

Specific procedure inquiry

Add III (Information) inside 2110C following the EQ:

EQ*30~
III*ZZ*99213~

Asks the payer for benefits specific to procedure 99213.

Validation

Check	Expected
Outbound 270 record appears with status submitted	Yes.
271 arrives with correlation_id matching the 270	Yes.
271 carries EB01 = 1 (active coverage) for an enrolled member	Yes.
Test envelope (ISA15 = T) does not bill the partner	Yes.

Troubleshooting

Symptom	Cause	Fix
271 returns AAA*N*…*72*… (subscriber not found)	Member ID typo, DOB mismatch, or coverage not yet effective	Confirm member identifiers; check coverage effective dates.
Outbound stalls in submitted status	Trading partner real-time endpoint timed out	Confirm partner status; rerun. Real-time partners typically respond within seconds; >30s is a partner-side issue.
Multi-service-type 270 returns only one EB	Partner does not honor multiple EQ per request	Split into multiple 270s.
270 routed to wrong partner	Routing rule misconfigured	See Submission routing rules under Claims; the same routing infra carries 270s.

Next

4.2 — 271 inbound — parsing the response