Parse and map every benefit loop in an X12 271 eligibility response to a structured coverage object

Steps

1. Obtain a 271 response from a clearinghouse or direct payer connection; confirm the ISA/GS envelope version is 005010X279A1 before processing.
2. Walk the loop hierarchy: Loop 2000A (information source), 2000B (information receiver), 2000C (subscriber), 2000D (dependent); use the EB01 eligibility or benefit information code to classify each EB segment as active coverage, deductible, co-insurance, co-pay, or out-of-pocket limit.
3. Extract EB03 (service type code), EB06 (benefit amount), EB07 (benefit percent), and DTP date ranges to build per-benefit-category coverage objects keyed by service type.
4. Check for AAA error segments at the subscriber or dependent loop level; AAA03 carries the reject reason code — surface these as structured errors rather than silently dropping the response.
5. Handle multi-valued INS and REF segments that indicate Medicare secondary payer status or coordination-of-benefits ordering to set adjudication priority.
6. Write unit tests covering at least: active coverage, inactive coverage, AAA rejection, and a dependent with a different deductible than the subscriber.