271 inbound — parsing the response

Outcome

A 271 response is parsed into structured eligibility data, the EB segments are interpreted correctly, AAA rejections are surfaced clearly, and the result is correlated to the originating 270 + member.

Prerequisites

The 270 was sent successfully (4.1 — 270 outbound). A registered partner with 271 inbound capability.

271 anatomy

Source: packages/x12/src/inbound/eligibility-271.ts. Implementation convention: 005010X279A1.

ISA → GS → ST*271 → BHT
  Loop 2000A — Information Source (echoes 270)
    HL*1**20*1
    NM1*PR
  Loop 2000B — Information Receiver (echoes 270)
    HL*2*1*21*1
    NM1*1P
  Loop 2000C — Subscriber
    HL*3*2*22*1
    NM1*IL (with payer's verified data)
    [REF] (additional identifiers)
    DMG (verified)
    DTP (effective dates of coverage)
    Loop 2110C — Eligibility / Benefit Information
      EB (one per benefit info)
      [REF] (plan / group identifiers)
      [DTP] (per-benefit dates)
      [AAA] (per-benefit error)
      [MSG] (free text)
SE → GE → IEA

Reading EB segments

The EB is the heart of the 271. One EB per benefit fact:

Element	Common values	Meaning
EB01	1 Active, 2 Active — Full Risk Capitation, 3 Active — Services Capitated, 4 Active — Pending Investigation, 5 Active — Pending Eligibility, 6 Inactive, 7 Inactive — Pending Eligibility, 8 Inactive — Pending Investigation, A Co-insurance, B Co-payment, C Deductible, D Benefit Description, F Limitations, G Out of Pocket (Stop Loss), I Non-Covered, R Other or Additional Payor	The benefit info code.
EB02	IND Individual, FAM Family	Coverage level.
EB03	Service type (echoes EQ01)	What benefit this EB covers.
EB04	12 PPO, 13 POS, 14 EPO, HM HMO, IP Indemnity, MD Medicare Part D, MA Medicare Part A, MB Medicare Part B, MC Medicaid, etc.	Insurance type.
EB05	Plan name	Free text.
EB06	7 Day, 21 Year-to-date, 22 Contract, 23 Years, 24 Episode, 25 Visit, 26 Outlier, 27 Remaining, 28 Exceeded, 29 Not Exceeded, 30 Lifetime, 31 Lifetime Remaining, 32 Interim, 33 Lifetime Maximum, 34 Lifetime — Calendar Year	Time period.
EB07	Amount	Cost share or limit.
EB08	Percent	Coinsurance percent.
EB09	Quantity qualifier	When EB10 carries a count.
EB10	Quantity	E.g. visits remaining.
EB11	Y In-network, N Out-of-network	Authorization required indicator.
EB12	Y In-Plan Network, N Out-of-Plan Network, U Unknown, W Not Applicable	In-plan network indicator.

Reading them in practice

EB*1*IND*30**HMO*Aetna PPO Plus~

→ Active coverage, individual, service type 30 (general health benefit plan), HMO insurance type, plan name "Aetna PPO Plus".

EB*C*IND*30****500.00~

→ Deductible, individual, service type 30, $500 deductible amount.

EB*B*IND*30****20.00~

→ Copayment, individual, service type 30, $20 copay.

EB*A*IND*30*****20~

→ Coinsurance, individual, service type 30, 20% coinsurance.

EB*F*IND*30*****20**VS*5~

→ Limitation, individual, service type 30, 20% coinsurance, Visit unit qualifier VS, 5 visits.

AAA — request rejections

AAA segments report errors. They can appear at the 2000C subscriber loop level (whole-request rejection) or inside an EB (per-benefit rejection).

AAA01	Meaning
Y	Valid request — the segment is informational.
N	Invalid — see AAA03.

AAA03 (Reject Reason Code)	Meaning
15	Required application data missing
41	Authorization / Access Restrictions
42	Unable to Respond at Current Time
43	Invalid / Missing Provider Identification
44	Invalid / Missing Provider Name
45	Invalid / Missing Provider Specialty
46	Invalid / Missing Provider Phone Number
47	Invalid / Missing Provider State
48	Invalid / Missing Referring Provider Identification Number
49	Provider is Not Primary Care Physician
50	Provider Ineligible for Inquiries
51	Provider Not on File
52	Service Dates Not Within Provider Plan Enrollment
53	Inquired Benefit Inconsistent with Provider Type
56	Inappropriate Date
57	Invalid / Missing Date(s) of Service
58	Invalid / Missing Date-of-Birth
60	Date of Birth Follows Date(s) of Service
61	Date of Death Precedes Date(s) of Service
62	Date of Service Not Within Allowable Inquiry Period
63	Date of Service in Future
64	Coverage Tier (Subscription) Not Found
65	Cannot Identify Member
66	Cannot Identify Subscriber
67	Cannot Identify Patient
68	Cannot Identify Insured
69	Subscriber Not in Group / Plan
70	Inappropriate Inquiry
71	Inappropriate Patient Identification Number
72	Invalid / Missing Subscriber / Insured ID
73	Invalid / Missing Subscriber / Insured Name
74	Invalid / Missing Subscriber / Insured Gender
75	Subscriber / Insured Not Found
76	Duplicate Subscriber / Insured ID
77	Subscriber Found, Patient Not Found
78	Subscriber / Insured Not in Plan or Group
79	Invalid Participant Identification

AAA04 is the follow-up action code — telling you how to retry:

AAA04	Meaning
C	Please correct and resubmit
N	Resubmission Not Allowed
P	Please resubmit original transaction
R	Resubmission allowed
S	Do not resubmit; we will hold your request and respond again shortly
W	Please wait 30 days and resubmit
X	Please wait 10 days and resubmit
Y	Do not resubmit; inquiry initiated to a third party

Reading the segment trace

/transactions/:id for a 271 shows the full envelope and per-loop breakdown. The page also exposes a Parsed result tab with the structured ParsedEligibility object the gateway derived — a JSON-shaped view of parseEligibility271().

Validation

Check	Expected
271 arrives with correlation_id to the 270	Yes.
EB01 = 1 for a known-active member	Yes.
AAA rejections surface as a structured error on the originating 270	Yes — visible on the rcm-app /eligibility page that triggered the request.
Multi-service-type 271 carries one EB per service type	Yes (when the partner honors multi-EQ requests).

Troubleshooting

Symptom	Cause	Fix
271 parsed but cost-share fields are empty	Generic 270 (EQ*30) did not request cost-share specifically	Re-run with a service-type-specific 270.
Plan name not in EB05	Some payers omit it	Read REF segments for the plan ID; cross-reference against your payer aliases.
EB01 = 4 "Active — Pending Investigation"	Coverage exists but payer is verifying enrollment	Wait the period named in any MSG text and re-run.
Multi-EB 271 has confusing overlapping limits	Per-service-type EBs can repeat with different time periods	Read EB06 time-period qualifier carefully; lifetime vs YTD vs visit-based limits do not aggregate.

Next

4.3 — Batch eligibility sweeps