HL7 IN1 Segment: Insurance Information
The HL7 IN1 segment (Insurance) carries health insurance plan information for a patient. It repeats for each insurance plan — primary, secondary, and tertiary coverage. IN1 appears in ADT, DFT, and other HL7 v2 message types, providing the payer data needed for eligibility verification, billing, and claims processing.
IN1 Field Reference
Section titled “IN1 Field Reference”| Seq | Name | Type | Opt | Description |
|---|---|---|---|---|
IN1-1 | Set ID | SI | R | Sequence number (1 = primary, 2 = secondary) |
| 1=Primary insurance, 2=Secondary, 3=Tertiary. Determines coordination of benefits (COB) billing order. | ||||
★ IN1-2 | Insurance Plan ID | CE | R | Plan code (e.g., BCBS001) |
| Identifies the specific insurance product. Payer ID mapping between systems is one of the most challenging integration tasks. | ||||
★ IN1-3 | Insurance Company ID | CX | R | Payer identifier |
| Used for electronic claims routing. Must map to standardized payer IDs for clean claims submission. | ||||
★ IN1-4 | Insurance Company Name | XON | O | Payer name |
IN1-5 | Insurance Company Address | XAD | O | Payer mailing address |
IN1-6 | Insurance Company Contact | XPN | O | Payer contact person |
IN1-7 | Insurance Company Phone | XTN | O | Payer phone number |
★ IN1-8 | Group Number | ST | O | Employer group number |
IN1-9 | Group Name | XON | O | Employer group name |
IN1-10 | Insured's Group Employer ID | CX | O | Employer identifier |
IN1-11 | Insured's Group Employer Name | XON | O | Employer name |
★ IN1-12 | Plan Effective Date | DT | O | Coverage start date |
★ IN1-13 | Plan Expiration Date | DT | O | Coverage end date |
IN1-14 | Authorization Information | AUI | O | Prior authorization details |
IN1-15 | Plan Type | IS | O | HMO, PPO, POS, etc. |
★ IN1-16 | Name of Insured | XPN | O | Subscriber name |
| When IN1-17 is not SELF, this differs from PID-5 — the subscriber is a different person than the patient. | ||||
★ IN1-17 | Insured's Relationship | CE | O | SELF, SPO, CHD, OTH |
| SELF=Patient is subscriber, SPO=Spouse, CHD=Child, EME=Employee, OTH=Other, UNK=Unknown. | ||||
IN1-18 | Insured's Date of Birth | TS | O | Subscriber DOB |
IN1-19 | Insured's Address | XAD | O | Subscriber address |
IN1-20 | Assignment of Benefits | IS | O | Whether benefits assign to provider |
IN1-21 | Coordination of Benefits | IS | O | COB priority |
IN1-22 | Coordination of Benefits Priority | ST | O | Numeric priority |
IN1-23 | Notice of Admission Flag | ID | O | Admit notification required |
IN1-24 | Notice of Admission Date | DT | O | When notice was given |
IN1-25 | Report of Eligibility Flag | ID | O | Eligibility reported |
IN1-26 | Report of Eligibility Date | DT | O | When eligibility was reported |
IN1-27 | Release Information Code | IS | O | Information release authorization |
IN1-28 | Pre-Admit Cert (PAC) | ST | O | Pre-admission certification number |
IN1-29 | Verification Date/Time | TS | O | When coverage was verified |
IN1-30 | Verification By | XCN | O | Who verified coverage |
IN1-35 | Company Plan Code | IS | O | Internal plan identifier |
★ IN1-36 | Policy Number | ST | O | Member/subscriber ID number |
IN1-46 | Prior Insurance Plan ID | IS | O | Previous plan identifier |
★ IN1-47 | Coverage Type | IS | O | B (Both), D (Dental), M (Medical), V (Vision) |
IN1-1 R Sequence number (1 = primary, 2 = secondary)
1=Primary insurance, 2=Secondary, 3=Tertiary. Determines coordination of benefits (COB) billing order.
★ IN1-2 R Plan code (e.g., BCBS001)
Identifies the specific insurance product. Payer ID mapping between systems is one of the most challenging integration tasks.
★ IN1-3 R Payer identifier
Used for electronic claims routing. Must map to standardized payer IDs for clean claims submission.
★ IN1-16 O Subscriber name
When IN1-17 is not SELF, this differs from PID-5 — the subscriber is a different person than the patient.
★ IN1-17 O SELF, SPO, CHD, OTH
SELF=Patient is subscriber, SPO=Spouse, CHD=Child, EME=Employee, OTH=Other, UNK=Unknown.
R = Required, O = Optional, C = Conditional, W = Withdrawn (backward compatibility only)
IN1-1: Set ID and Plan Ordering
Section titled “IN1-1: Set ID and Plan Ordering”The Set ID determines insurance plan priority:
| IN1-1 | Meaning | Billing Impact |
|---|---|---|
| 1 | Primary insurance | Claims submitted first |
| 2 | Secondary insurance | Claims submitted after primary adjudication |
| 3 | Tertiary insurance | Claims submitted after secondary adjudication |
Multiple IN1 segments appear in sequence, each with an incrementing Set ID. The billing system uses this ordering to determine coordination of benefits (COB) — which payer is billed first.
IN1-2 / IN1-3: Payer Identification
Section titled “IN1-2 / IN1-3: Payer Identification”IN1-2 (Plan ID) and IN1-3 (Company ID) together identify the specific insurance product:
IN1|1|BCBS001^BLUE CROSS BLUE SHIELD|BCBS|PO BOX 12345^^COLUMBUS^OH^43216| Component | Value | Purpose |
|---|---|---|
| IN1-2.1 | BCBS001 | Plan code — identifies the specific product |
| IN1-2.2 | BLUE CROSS BLUE SHIELD | Plan display name |
| IN1-3 | BCBS | Company/payer identifier — used for electronic claims routing |
Payer ID mapping is one of the most challenging aspects of insurance integration. Sending systems may use internal plan codes that don’t match the receiving system’s payer table. Integration engines typically maintain a crosswalk table mapping sender plan codes to standardized payer IDs (e.g., BCBS of Ohio → payer ID 00520).
IN1-17: Insured’s Relationship to Patient
Section titled “IN1-17: Insured’s Relationship to Patient”| Code | Meaning | Description |
|---|---|---|
| SELF | Self | Patient is the subscriber |
| SPO | Spouse | Covered through spouse’s plan |
| CHD | Child | Covered through parent’s plan |
| EME | Employee | Employee on employer plan |
| OTH | Other | Other dependent relationship |
| UNK | Unknown | Relationship not determined |
When IN1-17 is not SELF, IN1-16 (Name of Insured) will differ from PID-5 (Patient Name) — the subscriber is a different person than the patient.
IN1-47: Coverage Type
Section titled “IN1-47: Coverage Type”| Code | Meaning | Description |
|---|---|---|
| B | Both | Medical and dental coverage |
| D | Dental | Dental coverage only |
| M | Medical | Medical coverage only |
| V | Vision | Vision coverage only |
Key Implementation Considerations
Section titled “Key Implementation Considerations”Multiple Insurance Plans
Section titled “Multiple Insurance Plans”Patients commonly have 2-3 insurance plans. The integration must handle:
- Plan sequencing: IN1-1 determines primary/secondary/tertiary order
- Coordination of Benefits (COB): IN1-21 and IN1-22 define how payers coordinate payment
- Coverage verification: Each plan must be verified independently
- ADT^A08 updates: Insurance changes trigger ADT updates that must refresh all IN1 segments — not just the changed plan
IN1 vs IN2 (Extended Insurance)
Section titled “IN1 vs IN2 (Extended Insurance)”IN2 carries additional insurance fields that extend IN1:
- IN2-1: Insured’s Employee ID
- IN2-3: Insured’s Employer Name
- IN2-6: Medicare Health Insurance Card Number
- IN2-8: Medicaid Case Name
- IN2-25: Payor ID
Most interfaces use IN1 alone. IN2 is populated when the receiving system needs extended eligibility data — typically for government payer programs (Medicare, Medicaid) or complex employer group configurations.
Eligibility Verification Interfaces
Section titled “Eligibility Verification Interfaces”Real-time eligibility verification (270/271 transactions) is separate from IN1 in HL7 messages, but the data overlaps:
- IN1 carries insurance on file — what the patient reported during registration
- 270/271 carries verified coverage — confirmed active coverage from the payer
Integration engines should flag mismatches between IN1 data (reported) and 271 responses (verified) for registration staff to resolve before billing.
Payer ID Mapping Challenges
Section titled “Payer ID Mapping Challenges”The most common integration issue with IN1 segments is payer identification mismatches:
- Sending systems may use internal codes (BCBS001) vs. standard payer IDs (00520)
- Plan names may be truncated or spelled differently across systems
- Mergers and acquisitions change payer names and IDs
- Regional vs. national plan codes may differ
Maintaining an accurate, up-to-date payer crosswalk table is essential for clean claims submission.