Rivius Client Service Agreement

Version: 1.0, September 1, 2026 · Effective date: the date the Client signs electronically (the "Effective Date")

This Client Service Agreement (the "Agreement") is between Rivius Health ("Rivius"), and the medical practice, facility or other health care provider named on the sign-up form (the "Client").

Key terms in plain words

This summary is part of the Agreement. If it conflicts with the detailed sections, the detailed sections control.

• What we do: file federal No Surprises Act disputes for you, follow up on awards insurers have not paid, and appeal denied commercial claims. You can switch any of these off.
• What it costs: 12% of the extra money that actually reaches you because of our work, matched to your remittances line by line. No setup fee, no minimum, no subscription.
• Federal fees: the government's administrative fee and the arbiter's fee are yours to pay, at cost, with no mark-up. The arbiter refunds its fee to whichever side wins.
• How you pay: we invoice monthly. You get 10 days to check each invoice before we charge the payment method you saved with Stripe.
• No lock-in: month to month, no exclusivity. Cancel any time from your dashboard or by email.
• When you cancel: we finish disputes and appeals already filed and charge 12% only on money collected on those. Nothing else survives. You can export all your data at any time, free.
• We are not a law firm and do not give legal advice.

1. Definitions

• "Award" means a payment determination by a certified IDR entity in a Federal IDR Dispute, or an out-of-network rate agreed with a payer during open negotiation or during the Federal IDR process.
• "Client Data" means all data the Client or its agents give Rivius, and all data Rivius creates for the Client in providing the Services, including claim, dispute, Award, payment and appeal records.
• "Collected Amount" is defined in Schedule A.
• "Covered Claim" means a claim billed by the Client under its own TIN and NPI(s) to a commercial health plan or health insurance issuer, that the Client has not excluded under section 2.4, and on which Rivius performs a Service.
• "Federal IDR Dispute" means a dispute under the federal independent dispute resolution process under the No Surprises Act, including 45 CFR 149.510, 29 CFR 2590.716-8 and 26 CFR 54.9816-8, including the open negotiation period that must come before it.
• "Filed Matter" means (a) a Federal IDR Dispute for which Rivius submitted the notice of IDR initiation before the Termination Date, and (b) an appeal or reconsideration request that Rivius submitted to a payer before the Termination Date. An open negotiation that Rivius has started but not yet initiated in IDR is not a Filed Matter, unless the Client elects otherwise under section 9.3.
• "HIPAA" means the Health Insurance Portability and Accountability Act of 1996, the HITECH Act and their regulations at 45 CFR Parts 160 and 164.
• "Pass-Through Fees" means the federal IDR administrative fee and the certified IDR entity fee described in section 5, and any similar fee charged by a government body or payer that the Client approves.
• "Remittance" means an electronic remittance advice (ASC X12 835), explanation of benefits, payment notice or bank record showing a payment to the Client on a Covered Claim.
• "Services" means the services in section 2.
• "Termination Date" means the date termination of this Agreement takes effect under section 9.
• "US Operator" means an individual who works for Rivius (as an employee or contractor), has passed the identity verification that the federal IDR portal requires, and is physically located in the United States when using it.

2. The Services

2.1 Federal IDR

Rivius will, for Covered Claims it finds eligible:

• review the Client's Remittances to identify out-of-network claims that may be eligible for the Federal IDR process;
• check whether a claim is subject to the federal process or a state process, and not file where a state process applies;
• send open negotiation notices and handle open negotiation;
• decide, under the filing policy in section 2.5, whether to initiate a Federal IDR Dispute, and batch eligible claims as the rules allow;
• initiate disputes, take part in selecting the certified IDR entity, prepare and submit offers and supporting information, answer requests for information, and manage deadlines; and
• report every step and outcome in the Client's dashboard.

2.2 Award follow-up

Rivius will track each Award it obtains, and any earlier Award the Client assigns to it, against the 30-day payment deadline and the Client's Remittances. If a payer does not pay an Award in full and on time, Rivius may send reminders to the payer and prepare and submit complaints to the Centers for Medicare & Medicaid Services, the U.S. Department of Labor, the Office of Personnel Management or the relevant state insurance regulator, as appropriate. All communications are sent in the Client's name, with Rivius identified as its representative. Rivius does not sue payers, threaten litigation, hire lawyers for the Client, or receive payments for the Client.

2.3 Commercial denial appeals

Rivius will review denied Covered Claims, sort them into corrections and appeals, and prepare and submit corrected claims, reconsideration requests and appeals to the payer before the payer's deadline, using the payer's portal or other channel. Where a payer requires the patient's written authorisation for an appeal, Rivius will tell the Client and will not submit the appeal without it.

2.4 What is not included

• Claims paid, or to be paid, by Medicare, Medicaid, TRICARE or any other government health program.
• Lawsuits, arbitration outside the Federal IDR process, and any legal advice or legal representation.
• State surprise-billing dispute processes, unless added in writing.
• Contacting patients, or billing or collecting from patients.
• Any claim, Award or appeal the Client excludes in the dashboard or by email, including claims covered by another vendor's contract (section 7).

2.5 Filing policy

Rivius will initiate a Federal IDR Dispute only where, in its reasonable judgement, the expected result on the claim or batch is greater than the Pass-Through Fees the Client would bear. Rivius will show the reason for every eligible claim it decides not to file. The Client may tell Rivius in writing to file, or not to file, any claim. If the Client tells Rivius to file against its recommendation, the Client accepts the risk of the Pass-Through Fees on that claim.

2.6 How the work is done

• Every submission to the federal IDR portal is made by a US Operator.
• Rivius uses software, including artificial intelligence tools, to read Remittances, check eligibility and prepare filings. A person reviews every submission before it is sent.
• Rivius handles protected health information only as set out in the Business Associate Agreement.
• Rivius will follow the federal IDR portal's rules, including its rules against entering protected health information in portal fields and against access from outside the United States.

2.7 The Client controls amounts, offers and settlements

• The Client sets, and at all times controls, the amounts it charges and the amounts it will accept. Rivius recommends offers and negotiating positions; the Client approves them, either one by one in the dashboard or by setting rules in Schedule C (for example, "submit Rivius's recommended offer unless I object within 2 business days").
• Rivius may accept a payer's offer in open negotiation or during the Federal IDR process only if the offer meets the settlement rule the Client sets in Schedule C, or with the Client's written approval (email or dashboard is enough).
• The Client may change these rules at any time.

3. The Client's responsibilities

The Client will:

• provide Remittances for Covered Claims, either through a clearinghouse connection, a billing-company invitation or upload, and keep that feed current (at least monthly);
• answer Rivius's reasonable requests for information and documents within the time Rivius states, so deadlines can be met;
• tell Rivius promptly about any payment, settlement, recoupment or payer communication on a Covered Claim that does not appear in its Remittances;
• keep a valid payment method on file (section 4.3);
• sign any payer-specific or government form needed for Rivius to act for it; and
• not ask Rivius to submit anything the Client knows is false or misleading.

Rivius is not responsible for a missed deadline or lost claim caused by the Client's late or incomplete information.

4. Fees and payment

4.1 The fee

The Client pays Rivius twelve percent (12%) of the Collected Amount on each Covered Claim, as defined and calculated in Schedule A. There is no setup fee, subscription, minimum or charge of any other kind, except Pass-Through Fees under section 5.

State alternative: where the law of the Client's state does not permit a percentage fee for part or all of the Services, Schedule B applies to those Services instead of the percentage fee.

4.2 Matching and invoices

• Rivius matches each payment to the claim line it relates to, using the Client's Remittances. The dashboard shows, for each Collected Amount: the payer, claim reference, date of service, the Service that produced it, the amount paid before Rivius's work, the amount paid after, and the date received.
• On or about the 5th business day of each month, Rivius issues an invoice for Collected Amounts matched during the previous month. Invoices are delivered through the Client's secure dashboard, with a notice by email that does not contain patient information.

4.3 Stripe payment authorisation

By saving a payment method at sign-up, the Client authorises Rivius, through its payment processor Stripe, to charge that payment method, without further approval each time:

• (a) for each invoice under section 4.2, on or after the 10th day after the invoice date, for the invoice amount less any amount the Client has disputed under section 4.5; and

• (b) for Pass-Through Fees under section 5, if Option B in section 5 applies, when Rivius pays them for the Client.

• Timing and frequency: charges are unscheduled. They happen only after a Collected Amount has been matched and invoiced, normally no more than once a month, plus any Pass-Through Fee charges under (b).

• How the amount is set: 12% of the Collected Amounts on the invoice, calculated under Schedule A, or the exact Pass-Through Fee shown in the dashboard. The amounts will vary.
• Receipts: Rivius will email a receipt for each charge.
• Changing or cancelling: the Client can change or remove its payment method at any time in the dashboard, and can cancel this authorisation by ending the Agreement under section 9. The Client must keep a valid method on file while any fee is due.
• Record: Rivius keeps a record of this authorisation, including the date, time and signer.

At sign-up (checkbox next to the payment form): "☐ I authorise Rivius Health to save this payment method and charge it, without asking me each time, for (a) 12% of amounts actually collected on my practice's claims, as invoiced under the Client Service Agreement, after the 10-day review period, and (b) federal IDR fees paid for my practice at cost. Charges vary in amount and happen only after money arrives or a fee is incurred. I can cancel by ending the agreement."

4.4 Late payment

If a charge fails, Rivius will tell the Client and retry. If an undisputed amount is still unpaid 15 days after the failed charge, Rivius may (a) pause new filings (but not work on Filed Matters), and (b) charge interest at 1% per month or the highest rate the law allows, whichever is lower.

4.5 Questioning a fee

The Client may question any invoice line within 30 days of the invoice date through the dashboard or by email. Rivius will not charge a questioned line until the question is resolved. Rivius will show the Remittance or other record for the line and answer within 10 business days. Both parties will act in good faith. If a line was wrong, Rivius will correct it and, if already charged, refund or credit the difference within 10 business days. Unresolved disagreements are handled under section 15.

4.6 Recoupments

If a payer later recoups, offsets or claws back all or part of a Collected Amount within 12 months after it was paid, Rivius will credit the fee it charged on the amount recouped against the next invoice, or refund it if no invoice follows.

4.7 Taxes

Fees do not include sales, use or similar taxes. The Client pays any such tax that applies, except taxes on Rivius's income.

5. Pass-Through Fees (federal IDR fees)

• Administrative fee: each party to a Federal IDR Dispute must pay a non-refundable administrative fee when the certified IDR entity is selected. For disputes initiated on or after June 11, 2026, it is $15 per party per dispute (45 CFR 149.510(d)(2)).
• Certified IDR entity fee: each party pays the certified IDR entity's fee no later than the date offers are submitted. After deciding, the IDR entity keeps the fee paid by the non-prevailing party and must return the prevailing party's fee within 30 business days (45 CFR 149.510(d)(1)). Fees vary by IDR entity within ranges set by the federal government.
• These fees are the Client's cost. Rivius passes them through at cost, without mark-up, and shows each one in the dashboard before it is incurred. Rivius does not charge its 12% on returned IDR-entity fees.
• Monthly cap: Rivius will not incur Pass-Through Fees beyond the monthly cap in Schedule C without the Client's approval.

How they are paid. The Client pays each fee to the certified IDR entity or payment channel from its own account, using the payment instructions Rivius forwards. Refunds of a certified IDR entity fee go straight to the Client, and Rivius never holds Client money.

Where a certified IDR entity will only bill Rivius as the Client's representative, Rivius tells the Client before the fee is incurred, pays it for the Client and charges the same amount, at cost, to the saved payment method under section 4.3(b). Any refund that IDR entity pays to Rivius on the Client's dispute belongs to the Client: Rivius refunds it to the Client's payment method or credits it within 10 business days of receipt, and shows it in the dashboard.

Who is responsible to the government: under the 2026 IDR Operations rule, the representative's attestation may state whether the representative or the disputing party is obligated to pay the administrative fee and incurs the debt for non-payment (91 FR 33984-85). In its attestations, Rivius states that the Client is so obligated.

6. Term

This Agreement starts on the Effective Date and continues month to month until either party ends it under section 9. There is no minimum term, no automatic renewal for a fixed period, and no fee for ending it.

7. No exclusivity

• The Client may use other vendors, lawyers or its own staff for any claim, Award or appeal, at any time.
• To avoid duplicate filings, the Client will not assign the same claim or Award to anyone else while Rivius is working on it, and will tell Rivius about any claim that is covered by another vendor's contract. Rivius will exclude it.
• Rivius may provide services to other providers, including the Client's competitors.

8. Client Data and export

• Ownership: the Client owns Client Data. Rivius may use it only to provide the Services, as the Business Associate Agreement allows, and as section 11 allows.
• Export at any time: the Client may export its Client Data at any time from the dashboard, free of charge, in common machine-readable formats (for example CSV and JSON), together with copies of documents Rivius submitted for it.
• At termination: within 30 days after the Termination Date, and again when the last Filed Matter closes, Rivius will make a complete export available. After that, Rivius will return or destroy protected health information as the Business Associate Agreement requires.

9. Ending the Agreement

9.1 By the Client

The Client may end this Agreement at any time, for any reason, from the dashboard or by email to support@riviushealth.com. It ends at 11:59 p.m. Eastern Time on the day notice is received, or on a later date the Client states.

9.2 By Rivius

Rivius may end this Agreement on 30 days' notice for any reason, or at once by notice if the Client materially breaches it (including the Business Associate Agreement) and does not cure the breach within 10 days after notice, or if continuing would be unlawful.

9.3 What happens after termination (the only terms that survive)

• No new work. From the Termination Date, Rivius starts no new open negotiations, disputes, follow-ups or appeals.
• Open negotiations not yet in IDR. Rivius hands them over to the Client with all documents and dates, within 2 business days. No fee applies to them. The Client may instead elect in writing, within 5 business days, to have Rivius finish specific ones as Filed Matters.
• Filed Matters. Rivius finishes each Filed Matter, including follow-up of any resulting Award, unless the Client asks it to stop. The fee in section 4 applies only to Collected Amounts on Filed Matters that are received within 12 months after the Termination Date.
• If the Client asks Rivius to stop a Filed Matter, Rivius stops and hands it over. If an Award or appeal decision had already been issued, the fee still applies to amounts later collected on it within the sunset period. Otherwise, no fee applies to that matter.
• Nothing else survives. No fee applies to any other claim, Award or appeal, whether or not Rivius identified, reviewed or discussed it. The Authorization ends except for Filed Matters, and ends completely when the last Filed Matter closes.
• Also surviving: payment of amounts already due, sections 8 (data export), 10 (confidentiality), 12 (limitation of liability), 13 (indemnities), 15 (disputes) and 16 (general), and the Business Associate Agreement's terms on protected health information.

10. Confidentiality

Each party will keep the other's non-public business information confidential, use it only for this Agreement, and protect it with at least reasonable care. This does not cover information that is public through no fault of the receiving party, was already lawfully known to it, is independently developed, or must be disclosed by law (after notice to the other party where lawful). Protected health information is governed by the Business Associate Agreement, which controls over this section.

11. Aggregated and de-identified data

Rivius may create de-identified information from protected health information only as the Business Associate Agreement permits and in line with 45 CFR 164.514, and may use de-identified and aggregated data (for example, payer payment speed across clients) to improve its services and publish market statistics that do not identify the Client or any patient.

12. Warranties

12.1 The Client

The Client represents and warrants that:

• it has full authority to enter into this Agreement, and the person signing has authority to bind it;
• the claims it gives Rivius are its own, billed under its own TIN and NPI(s), and it has not assigned them to anyone else;
• the information and Remittances it provides are accurate and complete to the best of its knowledge, and it will correct errors promptly;
• it is not party to any exclusive contract or power of attorney that prevents it from using Rivius for the Services on the claims it gives Rivius, or it has disclosed and excluded the claims such a contract covers;
• it has the legal right to share protected health information with Rivius for the Services, including through any notice of privacy practices HIPAA requires; and
• it complies with the No Surprises Act's patient protections, including limits on billing patients, for claims it gives Rivius.

12.2 Rivius

Rivius represents and warrants that:

• it will perform the Services with reasonable care and skill, in line with industry practice;
• it will comply with laws that apply to it in performing the Services, including the federal IDR rules and HIPAA as a business associate; and
• every person who submits filings for the Client through the federal IDR portal will be a US Operator.

12.3 No guarantee of results

Rivius does not guarantee that any claim is eligible, that any dispute or appeal will succeed, that any payer will pay, or any amount or timing. Outcomes depend on certified IDR entities, payers and regulators. Except as stated in this section, each party disclaims all other warranties, express or implied, to the extent the law allows.

13. Indemnities

• By the Client: the Client will defend and indemnify Rivius against third-party claims arising from (a) a breach of its warranties in section 12.1, including any claim by another vendor that the Client breached an exclusive contract, or (b) inaccurate information the Client supplied.
• By Rivius: Rivius will defend and indemnify the Client against third-party claims, and fines imposed by a government body, arising from (a) Rivius's breach of the Business Associate Agreement, or (b) Rivius's gross negligence, wilful misconduct or violation of law in performing the Services.
• The indemnified party must give prompt notice, reasonable cooperation, and control of the defence to the indemnifying party, which may not settle a claim that admits fault by the indemnified party without its consent.

14. Limitation of liability and insurance

14.1 Limits

• Neither party is liable for indirect, incidental, special, consequential or punitive damages, or lost profits, even if foreseeable, except under section 13 or for breach of section 10 or the Business Associate Agreement.
• Rivius's total liability arising from this Agreement is limited to the total fees the Client paid Rivius in the twelve (12) months before the event giving rise to the claim.
• For breach of the Business Associate Agreement or section 10, and for Rivius's indemnity in section 13, Rivius's total liability is limited to the greater of those fees and the limits of the insurance Rivius maintains under section 14.2.
• None of these limits apply to fraud, wilful misconduct or any liability the law does not allow to be limited.
• Missed deadlines: if Rivius misses a deadline within its control that makes a claim ineligible, Rivius will reimburse any Pass-Through Fees lost on that claim.

14.2 Insurance

While this Agreement is in effect, and for 2 years after, Rivius will maintain professional liability (errors and omissions) insurance and cyber liability insurance, each from a reputable insurer and with limits appropriate to the Services. Rivius will provide a certificate of insurance on request.

15. Governing law and disputes

• This Agreement is governed by the laws of the State of Delaware, without regard to conflict-of-law rules, and by applicable federal law.
• Before starting any formal proceeding, the parties will try in good faith to resolve a dispute by written notice and discussion between senior representatives for 30 days.
• Any proceeding will be brought only in the state or federal courts located in New Castle County, Delaware.
• Either party may seek urgent injunctive relief to protect confidential information or protected health information in any competent court.

16. General

• Relationship: Rivius is an independent contractor. Nothing in this Agreement makes the parties partners, joint venturers or employer and employee.
• Not a law firm: Rivius is not a law firm, does not give legal advice and does not provide legal representation. If the Client needs a lawyer, it should hire one directly. Rivius does not pay or accept referral fees from lawyers.
• Subcontractors: Rivius may use subcontractors, including cloud and software providers and US Operators who are contractors, if they are bound by written terms at least as protective as this Agreement and, where they handle protected health information, by a business associate agreement as HIPAA requires. Rivius remains responsible for them.
• Client listing (opt-in): see section 17.
• Changes: Rivius may change this Agreement by giving at least 30 days' notice by email and in the dashboard. If the Client does not agree, it may end the Agreement before the change takes effect, and the earlier terms will apply to its Filed Matters. No fee increase will apply to work started before the change.
• Order of precedence: for protected health information, the Business Associate Agreement controls. Otherwise, this Agreement controls over the Authorization and the website Terms of Use.
• Electronic signature and records: the parties agree to do business electronically. Each party's electronic signature or click-acceptance has the same effect as a handwritten signature under the federal Electronic Signatures in Global and National Commerce Act (15 U.S.C. 7001 et seq.) and the Uniform Electronic Transactions Act as adopted in Delaware. Rivius will keep a record of the signed version, the signer's name and email, the date and time, and the IP address, and will email the Client a copy. The Client may ask for a paper copy at no charge.
• Notices: notices go by email to the addresses in the Client's account and to support@riviushealth.com for Rivius, and take effect on sending unless a bounce is received.
• Assignment: neither party may assign this Agreement without the other's consent, except to a successor to all or substantially all of its business that agrees to be bound by it (with notice to the other party).
• Force majeure: neither party is liable for delay caused by events beyond its reasonable control, including outages or suspensions of the federal IDR portal, government shutdowns or court orders affecting the Federal IDR process. Deadlines set by law are not extended by this clause unless the government extends them.
• Entire agreement: this Agreement (with its Schedules), the Business Associate Agreement and the Authorization are the entire agreement on this subject and replace any earlier discussions. If a provision is unenforceable, the rest remains in effect. A waiver must be in writing.

17. Permission to name the Client (optional, off by default)

Rivius will not name the Client as a client, use its name or logo, or describe its results in any website, marketing or sales material unless the Client ticks the box below. The Client can withdraw permission at any time by email, and Rivius will remove the Client's name from its website within 10 business days.

☐ Optional. You may list Practice legal name · Client completes by name as a client on your website and in sales materials. I understand this does not allow you to use our logo, quote us or publish our results without separate written consent.

Schedule A: How the fee is calculated

A.1 Collected Amount. "Collected Amount" means money a payer actually pays to the Client on a Covered Claim, as shown in a Remittance, that is attributable to Rivius's work, as follows:

A.2 Always excluded: patient payments of any kind (including cost sharing); IDR-entity fees returned to the Client; amounts the payer later recoups (section 4.6); amounts on claims the Client excluded before Rivius acted; and amounts received after the sunset period in section 9.3.

A.3 Interest and penalties. Interest or late-payment amounts a payer pays on a Covered Claim are not included in the Collected Amount.

A.4 Payments not in Remittances. If Rivius has evidence (for example, a payer's or IDR entity's notice) that a payment was made on a Covered Claim but it does not appear in the Client's Remittances within 45 days, Rivius will ask the Client to confirm. Rivius will invoice only once the Client confirms receipt or provides the Remittance, or if the Client does not respond within 15 business days, in which case the Client may still show non-receipt under section 4.5 and receive a full credit.

A.5 Worked example. The payer paid $1,240 on a claim line. After an IDR Award, the payer pays a further $5,660. The Collected Amount is $5,660. The fee is 12% × $5,660 = $679.20. The Client keeps $4,980.80 of the additional payment, less any Pass-Through Fees on that dispute. (Illustration only; not a typical or guaranteed result.)

Schedule B: State alternative fee

Some states restrict percentage-based compensation for preparing claims, for collection, or for negotiating payment. Where the law of the Client's state does not permit the percentage fee in section 4.1 for part or all of the Services, Rivius charges a flat fee per matter for the affected Services instead: a fixed amount per Federal IDR Dispute initiated, per appeal submitted and per Award follow-up matter. The amounts are set out in the Client's sign-up record and shown in the dashboard before any matter is filed, and the percentage fee in section 4.1 does not apply to those Services.

Schedule C: Client choices at sign-up

• Services switched on: ☐ Federal IDR ☐ Award follow-up ☐ Denial appeals
• Monthly Pass-Through Fee cap: US$ Amount · Client completes (if left blank, Rivius incurs no Pass-Through Fee without the Client's approval)
• Offer approval (section 2.7): ☐ approve each offer myself · ☐ submit Rivius's recommended offer unless I object within 2 business days
• Settlement rule for open negotiation and IDR settlements: accept if at least Percentage · Client completes% of the approved offer, or Other rule · Client completes; otherwise ask me
• Payers, claims or Awards excluded (for example, those covered by another vendor's contract): List · Client completes
• Client listing permission (section 17): ☐ on (default off)