POST /claimprocs/Supplemental does not support WriteOff / DedApplied

[avdhutkotkar]

Hello Open Dental Team,

We are integrating with the Open Dental API (v25.2.7+). We have already implemented and deployed supplemental insurance payment creation against POST /claimprocs/Supplemental for the InsPayAmt field, and it is working well for us in production. We now want to extend the same workflow to also record WriteOff and DedApplied as part of the supplemental entry, and we've hit a gap between the API specification and the Open Dental UI that we'd like your guidance on.

What we observed
Current API specification — POST /claimprocs/Supplemental

Per the published API reference (opendental.com/site/apiclaimprocs.html), the endpoint's request body only documents and accepts two fields:

Field Req/Opt Notes
ClaimProcNum Required The original (non-supp) claimproc to attach to
InsPayAmt Optional Default 0
WriteOff and DedApplied are not part of the current specification for this endpoint — they are neither listed as accepted parameters nor documented as optional. Sending them has no effect:

POST /claimprocs/Supplemental
{
"ClaimProcNum": 40,
"InsPayAmt": 15.00,
"WriteOff": 5.00, // ← NOT in current API spec, ignored/rejected
"DedApplied": 10.00 // ← NOT in current API spec, ignored/rejected
}
→ The supplemental row is created with the InsPayAmt, but WriteOff and DedApplied are silently dropped because the endpoint does not support them.

UI behavior — same workflow, done manually:

In the Open Dental desktop client, when a user opens a claim → Payment → Supplemental (or "As Total" supplemental entry) and selects the original procedure line, the edit grid does expose editable columns for both Write-off and Deductible alongside the Ins Pay amount. The user can enter a delta in those columns at the same time as entering the supplemental insurance payment, and Open Dental persists all three values in one save, enforcing the "net write-off ≥ 0" rule internally.

Our questions
1. How should this scenario be handled through the API today? Given the current POST /claimprocs/Supplemental spec does not accept WriteOff or DedApplied, what is the officially recommended way for an integrator to record a supplemental insurance payment together with a write-off and/or deductible adjustment — particularly on claims where the original claimproc is already tied to a finalized ClaimPayment?

2. Is there a roadmap item to extend POST /claimprocs/Supplemental (or provide another endpoint) so that the API can match what the UI already allows in a single supplemental entry? If so, is there a target version or timeframe you can share?

Thank you for the support.

[justine]

Hello Open Dental Team,

We are integrating with the Open Dental API (v25.2.7+). We have already implemented and deployed supplemental insurance payment creation against POST /claimprocs/Supplemental for the InsPayAmt field, and it is working well for us in production. We now want to extend the same workflow to also record WriteOff and DedApplied as part of the supplemental entry, and we've hit a gap between the API specification and the Open Dental UI that we'd like your guidance on.

What we observed
Current API specification — POST /claimprocs/Supplemental

Per the published API reference (opendental.com/site/apiclaimprocs.html), the endpoint's request body only documents and accepts two fields:

Field Req/Opt Notes
ClaimProcNum Required The original (non-supp) claimproc to attach to
InsPayAmt Optional Default 0
WriteOff and DedApplied are not part of the current specification for this endpoint — they are neither listed as accepted parameters nor documented as optional. Sending them has no effect:

POST /claimprocs/Supplemental
{
"ClaimProcNum": 40,
"InsPayAmt": 15.00,
"WriteOff": 5.00, // ← NOT in current API spec, ignored/rejected
"DedApplied": 10.00 // ← NOT in current API spec, ignored/rejected
}
→ The supplemental row is created with the InsPayAmt, but WriteOff and DedApplied are silently dropped because the endpoint does not support them.

UI behavior — same workflow, done manually:

In the Open Dental desktop client, when a user opens a claim → Payment → Supplemental (or "As Total" supplemental entry) and selects the original procedure line, the edit grid does expose editable columns for both Write-off and Deductible alongside the Ins Pay amount. The user can enter a delta in those columns at the same time as entering the supplemental insurance payment, and Open Dental persists all three values in one save, enforcing the "net write-off ≥ 0" rule internally.

Our questions
1. How should this scenario be handled through the API today? Given the current POST /claimprocs/Supplemental spec does not accept WriteOff or DedApplied, what is the officially recommended way for an integrator to record a supplemental insurance payment together with a write-off and/or deductible adjustment — particularly on claims where the original claimproc is already tied to a finalized ClaimPayment?

2. Is there a roadmap item to extend POST /claimprocs/Supplemental (or provide another endpoint) so that the API can match what the UI already allows in a single supplemental entry? If so, is there a target version or timeframe you can share?

Thank you for the support.

Hello avdhutkotkar,

Thank you for the detailed explanation. To answer your questions:

1. After making the POST claimprocs/Supplemental call, use the ClaimProcNum of the newly created supplemental claimproc in a PUT claimprocs call to update the WriteOff and DedApplied fields.
2. No, there are no plans to change behavior at this time.

Thanks!

[avdhutkotkar]

Thank you for this workaround.