Construct an X12 837I institutional claim for an inpatient stay including all required UB-04 equivalent data elements in the correct loops and segments
In the 2300 claim information loop, set CLM05-01 to the appropriate facility type code and CLM05-02 to the claim frequency type code; for an inpatient claim, CLM05-01 is typically 11 for hospital inpatient and CLM05-02 is 1 for an original claim
Populate the CL1 segment in the 2300 loop with the admission type code, admission source code, and patient status code at discharge; these three elements correspond to UB-04 form locators 14, 15, and 17 and are required for inpatient institutional claims
Add HI segments to the 2300 loop to carry the principal diagnosis with qualifier ABK for ICD-10-CM, additional diagnosis codes with qualifier ABF, the principal procedure with qualifier BBQ for ICD-10-PCS, and the admitting diagnosis with qualifier ABJ; sequence the diagnosis codes in priority order as the payer will use sequence for DRG grouping
Build the 2300 DRG value composite in the HI segment only if the submitter has already grouped the claim and is transmitting the DRG; otherwise omit the DRG and allow the payer to group using the submitted diagnoses and procedures
In the 2400 service line loop, use SV2 instead of SV1 for revenue code-based line billing; SV201 is the revenue code, SV202 is the composite medical procedure identifier for the HCPCS or CPT code if applicable, SV203 is the charge amount, and SV205 is the billed units
Populate the 2300 AMT segments with condition code-equivalent amounts such as total covered days and non-covered days, and add CLM19 to indicate whether the claim has attached clinical documentation referenced by a PWK segment with the applicable attachment report type code
Known gotchas
ICD-10-PCS codes are required for inpatient institutional claims submitted to Medicare and many other payers; submitting a CPT-coded procedure on the HI segment using the PCS qualifier rather than a valid ICD-10-PCS code will produce a claim rejection or a DRG grouping error that reduces reimbursement
The patient status code in CL1 must reflect the actual discharge disposition at the time of claim submission; submitting a claim before the final discharge status is confirmed with a placeholder status code will generate a Medicare audit flag and may trigger a request for medical records
Revenue code 001 total charges is not permitted on individual service lines for electronic 837I submissions even though it appears on paper UB-04 forms; including revenue code 001 as a service line will cause the claim to reject with a line-level error rather than a header-level error
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claude mcp add --transport http waymark https://mcp.waymark.network/mcp