Learn · OON Underpayments

MultiPlan Out-of-Network Underpayment Resources

MultiPlan (now Claritev) is the largest third-party repricing company in the United States. When its platforms cut your out-of-network payment, the appeal goes to the insurer, not the vendor.

Written for providers and hospitals, billers, and patients.

MultiPlan (now operating as Claritev) is the largest third-party repricing company in the United States. It processes over 106 billion dollars in out-of-network claims annually for insurance companies. When your claim is repriced by one of MultiPlan's platforms (Data iSight, Viant, ProPricer, or MARs), the insurance company pays you less than your billed amount based on MultiPlan's algorithm.

The most important thing to know: you appeal the insurance company, not MultiPlan. The vendor only repriced the claim. The plan is the one legally responsible for paying you.

Appeal the insurer, not the vendor

MultiPlan is a vendor hired by the insurance company, and it does not owe you payment. The insurance company or plan administrator does. Direct every appeal to the plan's appeals department and ask it to override the MultiPlan repricing.

How it works

MultiPlan and its repricing platforms

When you see one of MultiPlan's platform names on your remittance notice, it means the insurance company hired MultiPlan to "reprice" your out-of-network claim to a lower amount before payment. MultiPlan owns and operates several repricing systems. Here is what each one does.

Data iSight

MultiPlan’s proprietary repricing algorithm. Claims processed through Data iSight are identified on remittance notices with "Data iSight" referenced. This platform handles a massive volume of out-of-network claims nationwide.

Viant

Another MultiPlan-owned repricing system. Viant claims are similarly identified on payment documents. Both Viant and Data iSight use similar algorithmic approaches to determine repriced payment amounts.

ProPricer

A MultiPlan subsidiary used for repricing specific claim types and specialties.

MARs

MultiPlan’s network management system. Check your remittance notices for any reference to these platforms.

How MultiPlan works

Instead of paying claims at your billed amount, the insurance company uses MultiPlan to "reprice" the claim. Claims are often reduced by 61 to 81 percent off billed charges, sometimes as low as 1 percent. MultiPlan receives a percentage of the underpayment savings, creating a financial incentive to lower payments.

Active federal antitrust litigation

MultiPlan and five major insurers are currently defendants in federal antitrust litigation (MDL 3121, Northern District of Illinois) alleging systematic underpayment of out-of-network claims. The case survived a motion to dismiss in June 2025 and is proceeding to discovery.

Providers who received out-of-network payments through MultiPlan platforms may be entitled to participate in this litigation. (Status as of June 2026; litigation moves quickly, so confirm the current status before relying on it.)

Step one

How to identify MultiPlan underpayments

Signs on your remittance notice

  • "Data iSight," "Viant," "ProPricer," or "MARs" explicitly mentioned in adjustment descriptions or remarks
  • Adjustment code CO-45 (contractual adjustment) with a reduction you did not authorize
  • Payment significantly below your expected or billed amount
  • A network name that does not match the patient's insurance card
  • A reduction with no explanation or remark code (hardest to catch)

Step-by-step identification

  • Examine each claim line on the remittance notice
  • Compare the allowed or paid amount to your billed charges
  • Look for "MultiPlan," "Data iSight," or repricing language in remarks
  • Build a spreadsheet of repriced claims to identify patterns over time

The process

How to appeal MultiPlan underpayments

Direct the appeal to the plan, document the repricing, and benchmark what you should have been paid.

  1. 1

    Appeal directly to your insurance company

    • Find the insurance company or plan contact on the patient's insurance card or remittance notice
    • Contact the plan's appeals or disputes department
    • Explain that your out-of-network claim was repriced by MultiPlan
    • Request the plan pay your full billed amount or a fair market rate
    • Provide your billed charges and market-rate benchmarking data

    See our ERISA appeals guide for additional appeal steps and timelines.

  2. 2

    Provide supporting documentation

    Document why the MultiPlan repricing was unfair. Specific regulatory forms vary by plan and state. The full checklist is in the next section.

Build your file

Documentation you will need to appeal

When you appeal the insurance company, provide documentation supporting why the MultiPlan repricing was unfair. Specific regulatory forms vary by plan and state. For detailed step-by-step documentation requirements, see our ERISA appeals guide. Here are the general document categories.

  • Your remittance notice showing the MultiPlan repricing adjustment
  • Your itemized bill for the service
  • CMS-1500 or UB-04 claim form you submitted
  • Complete medical records supporting medical necessity
  • Your billed charges or fee schedule for this service
  • Medicare fee schedule rates for your CPT code and geographic region
  • FAIR Health or specialty-specific benchmarking data showing what providers typically receive
  • Any correspondence with the insurance company about the repricing (note: OON providers have no direct insurance contract)
  • Required regulatory and appeal forms specific to your plan (varies by insurance company and state)

Federal litigation

Federal antitrust litigation (MDL 3121)

Multiple class actions consolidated in MDL 3121 allege MultiPlan and insurers engaged in price-fixing and systematic underpayment of out-of-network claims since 2016.

Who may qualify

  • Any provider or billing entity that received out-of-network payments repriced by MultiPlan, Data iSight, Viant, ProPricer, or MARs
  • Claims dating back to 2016

This status is time-sensitive

The figures and case status above reflect what was publicly reported as of June 2026. Litigation timelines, eligibility, and any settlement details can change. Confirm the current status before relying on it, and consult a qualified attorney about your specific situation.

Reference & tools

Find what you should be paid (OON benchmarking)

For out-of-network claims, you have no contract with the insurance company. Use these resources to find what Medicare and commercial insurers typically pay for your services in your geographic area.

Keep reading

Related guides

OON underpayments overview

How out-of-network repricing works and how to push back across vendors.

Read

Data iSight repricing

A MultiPlan platform behind many out-of-network reductions, and how to dispute it.

Read

Zelis repricing

Another common out-of-network repricing vendor and how to appeal it.

Read

ERISA appeals guide

The step-by-step appeal process for employer-sponsored health plans.

Read

Appeals glossary

Plain-English definitions of ERISA, IDR, QPA, SPD, and the rest.

Read

Appeal deadlines

Every filing window, in one reference.

Read

Disclaimer

This guide is for informational purposes only and does not constitute legal or medical advice. Appeal It Now provides administrative support and appeal preparation services only; we are not a law firm. Please consult a qualified professional for advice specific to your situation.

Version 2.0 · Updated June 2026