> ## Documentation Index
> Fetch the complete documentation index at: https://docs.withflex.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Compliance Hub

> How Flex determines HSA/FSA eligibility, meets IRS substantiation requirements, and works with telehealth partners.

Accepting HSA/FSA payments means operating inside the IRS's tax-advantaged account framework. That framework has one non-negotiable principle:

<Info>
  **Every HSA/FSA purchase must be substantiated as an eligible medical expense.**
</Info>

The Compliance Hub explains how Flex meets that requirement on your behalf — how we determine what qualifies, how our Inventory Information Approval System (IIAS) gates checkout, and how we work with telehealth partners so dual-purpose products can qualify through a Letter of Medical Necessity.

<CardGroup cols={3}>
  <Card title="How Flex Determines Eligibility" icon="scale" href="/compliance/how-eligibility-works">
    The legal foundation — IRC §213(d), Publication 502, and the line between medical treatment and general wellness.
  </Card>

  <Card title="Flex's IIAS" icon="shield-check" href="/compliance/iias">
    What the IRS requires of an Inventory Information Approval System, who needs one, and how Flex satisfies each requirement.
  </Card>

  <Card title="Telehealth Partnerships" icon="stethoscope" href="/compliance/telehealth-partnerships">
    How Flex partners with licensed telehealth providers to build telehealth consultations which fit our merchants' products and services, and provide Letters of Medical Necessity from telehealth visits.
  </Card>
</CardGroup>

## The three outcomes that drive checkout

Every product in your catalog resolves to one of three checkout behaviors. Everything else in this hub is an elaboration of these:

| Outcome                | What it means                                                                                                                                                               | Customer experience                                                                                                       |
| ---------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------- |
| **Auto-substantiated** | The product qualifies as a medical expense on its own. Flex approves it through our IIAS.                                                                                   | Pays with an HSA/FSA card. No extra steps.                                                                                |
| **Dual-purpose (LMN)** | The customer can qualify to purchase the product when their primary purpose of purchase is to treat, mitigate, or alleviate a diagnosed condition, but needs documentation. | Completes a telehealth consultation at checkout; a licensed clinician issues a Letter of Medical Necessity upon approval. |
| **Not eligible**       | The product does not qualify as a medical expense.                                                                                                                          | Pays with a credit or debit card. In a mixed cart, this portion falls to the remainder.                                   |

<Note>
  This documentation explains how Flex applies IRS guidance to product eligibility. It is not legal or tax advice. Employer-sponsored FSA and HRA plans may apply stricter standards than the IRS baseline — see [How Flex Determines Eligibility](/compliance/how-eligibility-works#hsa-vs-fsa-differences) for what that means in practice.
</Note>

## Questions

For eligibility determinations, catalog reviews, or documentation requests, contact [compliance@withflex.com](mailto:compliance@withflex.com). For everything else, reach your dedicated Partner Success Manager or [support@withflex.com](mailto:support@withflex.com).