837D file anatomy

This page maps the loops and segments in the 837D dental claim transaction (X12N 837 Health Care Claim: Dental, implementation guide 005010X224A2). It is intended for operators investigating a rejection and for engineers parsing claim files. For a conceptual walkthrough, see The 837D.

The loop hierarchy

X12 organizes data into nested loops. The 837D shares its skeleton with the other 837 variants; the dental content lives in the claim and service-line loops:

Loop	Contains
1000A	Submitter
1000B	Receiver
2000A	Billing provider hierarchical level
2010AA	Billing provider, usually the professional entity: name, NPI, Tax ID, and address
2010AB	Pay-to address, if different
2000B	Subscriber hierarchical level
2010BA	Subscriber, member ID, name, DOB
2010BB	Payer
2000C	Patient hierarchical level (only when the patient is not the subscriber; routine in dentistry, where the patient is very often a covered child)
2010CA	Patient
2300	Claim: total charge, frequency code, predetermination indicator, preauthorization number, attachment reference, orthodontic fields
2310	Claim-level providers: referring dentist, rendering dentist (the individual, Type 1 NPI), service facility location
2320/2330	Coordination-of-benefits loops: the other payer and, on a secondary claim, the primary’s adjudication
2400	Service line, one per CDT procedure: charge, date, tooth and oral-cavity detail

Annotated example

An 837D fragment with each segment explained. Element positions inside the dental segments are simplified; your payer’s companion guide is authoritative for the exact layout.¹

ISA*00*          *00*          *ZZ*SUBMITTERID    *ZZ*PAYERID        *260813*1200*^*00501*000000001*0*P*:~
GS*HC*SUBMITTERID*PAYERID*20260813*1200*1*X*005010X224A2~
ST*837*0001*005010X224A2~
BHT*0019*00*REF123*20260813*1200*CH~
NM1*41*2*BLUEBIRD DENTAL*****46*SUBMITTERID~
NM1*40*2*SAMPLE DENTAL PAYER*****46*PAYERID~
HL*1**20*1~
NM1*85*2*MAYA OKAFOR DDS PC*****XX*1234567890~
N3*100 MAIN ST~
N4*COLUMBUS*OH*43215~
REF*EI*880000000~
PRV*BI*PXC*122300000X~
HL*2*1*22*0~
SBR*P*18*******CI~
NM1*IL*1*CHEN*MARGARET****MI*ABC123456789~
DMG*D8*19710415*F~
NM1*PR*2*SAMPLE DENTAL PAYER*****PI*PAYERID~
CLM*PATACCT001*452.00***11:B:1*Y*A*Y*Y~
NM1*82*1*OKAFOR*MAYA****XX*1987654321~
LX*1~
SV3*AD:D1110*142.00~
DTP*472*D8*20260801~
LX*2~
SV3*AD:D2391*310.00****1~
TOO*JP*30*O~
DTP*472*D8*20260801~
SE*25*0001~
GE*1*1~
IEA*1*000000001~

Segment by segment

Segment	Meaning
`ISA`	Interchange envelope: sender, receiver, date, control number, delimiters
`GS`	Functional group. `HC` = health care claim. `005010X224A2` identifies the 837D implementation guide
`ST`	Transaction set start
`BHT`	Beginning of hierarchical transaction. `CH` = chargeable; an actual claim rather than a report
`NM1*41`	Submitter, who transmitted the file; often your clearinghouse configuration, and where a multi-PC group misroutes claims
`NM1*40`	Receiver
`HL1201`	Hierarchical level: `20` = information source (billing provider)
`NM1*85`	Billing provider. `2` means organization and `XX` qualifies the NPI. Use the enrolled legal name, which may differ from the brand
`N3` / `N4`	Address
`REF*EI`	Employer ID, the Tax ID
`PRVBIPXC*...`	Billing provider taxonomy. `PXC` qualifies a taxonomy code; here `122300000X`, dentist. See Taxonomy codes
`HL21220`	`22` = subscriber level
`SBRP18...CI`	Subscriber: `P` = primary, `18` = self, `CI` = commercial insurance
`NM1*IL`	Subscriber. `MI` qualifies the member ID
`DMGD8...`	Demographics: date format `D8` = CCYYMMDD
`NM1*PR`	Payer
`CLM`	Claim: patient account number, total charge, then the composite `11:B:1` carrying the place-of-treatment code and the claim frequency code (`1` original)
`NM1*82`	Rendering dentist, the individual’s Type 1 NPI; must be credentialed and linked to the group contract
`LX`	Service line counter
`SV3AD:D1110142.00`	Dental service line. `SV3` is the dental line segment; the 837P uses `SV1`. `AD` qualifies a CDT code. This example reports D1110, adult prophylaxis, which does not need a tooth number
`SV3AD:D2391310.00...`	Second line: D2391, a one-surface posterior composite
`TOOJP30*O`	Tooth information, which does not appear on a medical claim: tooth `30`, occlusal surface `O`
`DTP472D8*...`	Service date. `472` = service
`SE` / `GE` / `IEA`	Transaction, group, and interchange trailers with segment counts

The dental-specific content

What separates an 837D from the other 837 variants, beyond the code set:¹

Element	What it carries	Why it exists
CDT service lines (`SV3`, `AD` qualifier)	“D” plus four digits per procedure	CDT is the HIPAA-designated dental code set; see CDT & the 837D
Tooth information (`TOO`)	Tooth number and surface codes	Lets the payer enforce per-tooth history: a crown’s replacement interval, a missing tooth clause, prior restorations on the same surface
Oral cavity designation	Quadrant, arch, or area at the service line	Quadrant-based procedures; scaling and root planing is adjudicated per quadrant
Orthodontic fields	Banding date and months of treatment remaining	Ortho’s installment-payment model runs on these; continuation claims without them pend
Predetermination indicator	Flags the transaction as a predetermination request rather than a chargeable claim	The payer returns an estimate for planned work instead of a payment; see Get predeterminations
COB loops	The other payer’s identity and, on secondary claims, the primary’s adjudication	Dental COB is routine; child patients under two parents’ plans, ordered by the birthday rule
Attachment reference	A claim-level pointer to documentation sent separately; an NEA number in the remarks, or the attachment control segment (`PWK`) where the companion guide specifies it	Many payers require radiographs or charting before adjudicating crowns, SRP, or implants; see Dental attachments
Diagnosis codes	ICD-10-CM, situational	Required by some payers and many Medicaid programs, not the organizing principle it is in medical billing

The implementation guide defines where these fields belong, while each payer’s companion guide states which situational fields it requires.¹

Common rejection fields

Field	Location	Failure
Billing provider legal name	`NM1*85`	The brand name (“Bluebird Dental”) instead of the PC’s legal name; doesn’t match the payer’s records / the CP 575
Billing provider NPI	`NM1*85`, `XX` qualifier	Wrong entity’s Type 2 in a multi-PC group
Tax ID	`REF*EI`	Doesn’t match enrollment; post-acquisition, the seller’s TIN still configured
Taxonomy	`PRVBIPXC`	Doesn’t match the enrolled taxonomy
Rendering dentist NPI	`NM1*82`	Not credentialed or not linked to the group contract
Subscriber ID	`NM1*IL`, `MI` qualifier	Transposed digits; plan entered under the wrong parent
Date of birth	`DMG`	Doesn’t match the payer’s record
Tooth / surface data	`TOO` and service line	Missing tooth number where the code requires one; surface count inconsistent with the code (a one-surface code with two surfaces)
Oral cavity designation	Service line	Missing quadrant on a quadrant-based procedure
Preauthorization number	Claim level	Medicaid or DHMO preauthorization obtained but never entered in the structured field
Attachment reference	Claim remarks / `PWK`	Documentation uploaded but the claim never points to it
COB order	`SBR` / 2320 loops	Primary claim sent to the secondary plan
Claim frequency code	`CLM05` composite	`1` original, `7` replacement, `8` void; resubmitting an adjudicated claim as `1` denies as duplicate
Service date	`DTP*472`	Before the rendering dentist’s effective date

Many of these failures originate in enrollment or system configuration rather than the clinical claim. See Set up EDI, ERA, and EFT.

837P, the crossover format

The 837P (005010X222A1) is the professional medical claim. A dental group may use it for medically billable oral surgery, sleep appliances, trauma, or other services submitted to a patient’s medical plan. Important differences include:

Element	837D	837P
Implementation guide	`005010X224A2`	`005010X222A1`
Paper analogue	ADA Dental Claim Form	CMS-1500
Procedure codes	CDT (`AD` qualifier)	CPT/HCPCS (`HC` qualifier)
Service line segment	`SV3`	`SV1`
Tooth-level data	`TOO` segment, oral cavity designation	None
Diagnosis codes	Situational	Required; ICD-10-CM drives adjudication
Place of service	Place-of-treatment code	POS code with facility/non-facility payment consequences

Medical billing requires a different code set, documentation standard, and enrollment. It is not simply a conversion of the dental claim fields. See Bill medical plans for dental work and Place of service codes.

Corrected claims

Frequency code (`CLM05-3`)	Meaning
`1`	Original
`7`	Replacement of a prior claim
`8`	Void / cancel a prior claim

A 7 or 8 must reference the original claim number, typically in REF*F8 (payer claim control number); you’ll find that number in the 835’s CLP07.

Unless the payer instructs otherwise, do not resubmit an adjudicated claim with frequency code 1. It may deny as a duplicate (CARC 18) and consume the correction window.

Sources

X12N 837D implementation guide 005010X224A2; segment-level requirements and dental-content placement per payer companion guides: UnitedHealthcare, 837D companion guide, 005010X224A2 (PDF); Delta Dental, 837 companion guide (PDF); Stedi, Differences between 837P, 837D, and 837I claims.

CPOD & Legal

Payers

Clearinghouses & Vendors

EDI & Code Sets

Banking & Payments

Glossary & Appendices

The loop hierarchy

Annotated example

Segment by segment

The dental-specific content

Common rejection fields

837P, the crossover format

Corrected claims

Sources

​The loop hierarchy

​Annotated example

​Segment by segment

​The dental-specific content

​Common rejection fields

​837P, the crossover format

​Corrected claims

​Sources

The loop hierarchy

Annotated example

Segment by segment

The dental-specific content

Common rejection fields

837P, the crossover format

Corrected claims

Sources