Straight Through Processing (STP) API

A: Straight Though Processing (STP) API is a payment automation solution that uses partner merchant processors (like you) to automate the acceptance, settlement and posting of payer-issued virtual card C2B patient payments and B2B claim payments to health care providers. Instead of providers manually keying virtual cards, the entire process is handled electronically via API integrations. This helps to reduce administrative work and speed up payment posting, supporting both patient payments and insurer reimbursements.  

In short, STP connects payers, providers, merchant processors and patients to enable fully automated, instant payment posting in health care. 

A: Once you’re onboarded as an STP partner, the workflow is straightforward. First, providers enroll to use STP through your platform (with coordination from Optum). Then, when a payer disburses a virtual card payment, the payment details are routed to your system via the STP API. Your platform processes the card and posts the corresponding remittance data into the provider’s system (e.g., their EHR or billing system) in real time. There’s no need for the provider to key in the card or remittance — it’s all handled behind the scenes.  

If any issue occurs (for example, if a payment can’t be auto posted), STP will trigger a predefined exception callback or provide an exception file so the issue can be resolved quickly. In summary, the merchant processor plays the role of the automated card processor and reconciliation. You receive the card payment info via API, handle the transaction and feed the payment/remittance record into the provider’s accounts automatically. 

A: Integrating with STP offers tangible business benefits for merchant processors. First, it may increase your transaction volume. By making virtual card payments easier and more attractive for payers and providers, STP helps drives more electronic payments through your platform (instead of paper checks), translating to greater processing revenue.  

Second, STP requires only a one-time integration (a common API), which reduces the cost and complexity of adding new clients or payers. You connect once and can scale to many customers.  

Third, it helps give you a competitive edge. You’ll be offering a modern service that automates the former manual workflow, which improves customer satisfaction (faster payments, less work for their staff) and can attract more clients to your platform.  

STP can help grow your revenue while helping to enhance your operational efficiency and the value you deliver to customers.

A: STP is built to be robust and handle exceptions gracefully. If a payment or remittance can’t be auto posted for some reason (for example, a provider’s system is temporarily unavailable or there’s a data mismatch), the system will flag it as an exception. In such cases, STP will follow the agreed fallback process — typically either sending an exception file or notification to the merchant processor with details on the issue, invoking a callback on a designated error-handling endpoint. This way, your team is alerted to any payment that didn’t go through automatically and you can work to promptly resolve it (i.e., post it when the system is back online, or correct any data and reprocess).  

STP uses standardized remittance mapping that helps to decrease the instances of posting errors — the data format is consistent and tested, resulting in high accuracy. Exceptions are rare, but when they do occur, STP provides a mechanism to catch and fix them to help prevent transactions from falling through the cracks.

A: Yes — security and compliance are top priorities in STP’s design. All payment data (virtual card numbers, remittance details, patient information, etc.) is transmitted over encrypted, secure channels and the process is compliant with PCI-DSS (for payment data) and HIPAA requirements (for protected health information). By automating what used to be a manual, paper-driven process, STP helps reduce fraud risks.  

Optum and its partners undergo rigorous security reviews, so you can be confident that integrating with STP meets standard security certifications for health care payments. STP offers a secure, trusted platform for moving money and remittance data, which helps protect all parties involved. 

A: Optum Financial is committed to making integration successful for our partners. When you decide to integrate, we’ll provide comprehensive documentation — including an integration guide and full API specifications detailing each endpoint, authentication, data format, etc. to your technical team. You’ll have a dedicated point of contact at Optum (a solutions engineer or partnership manager) to coordinate your onboarding. This includes regular check-ins, assistance with testing, and validating the data flows work correctly in your environment.  

We also offer ongoing support after launch: If you or your clients encounter any issues, our support team (in collaboration with the merchant processor’s support) will help troubleshoot and resolve problems quickly. Essentially, we don’t just hand over the API and walk away. We work together with you through development, deployment and beyond to ensure STP delivers value. Many of our current merchant processors have noted that this close collaboration made the onboarding process smooth. You can expect the same level of partnership commitment as you integrate STP into your offerings.