Two Powerful Tools, One Goal: Fair Compensation
If you are an out-of-network physician, you already know that insurance companies routinely underpay your claims. What you may not realize is that federal law provides not one but two distinct pathways to challenge those underpayments—and most practices are only using one of them, if they are using either at all.
The first pathway is IDR (Independent Dispute Resolution), established by the No Surprises Act in 2022. It is a streamlined federal arbitration process designed specifically for out-of-network payment disputes. The second is ERISA appeals, a longer-standing framework under the Employee Retirement Income Security Act that governs employer-sponsored health plans—covering approximately 180 million Americans.
Each tool has distinct strengths, limitations, timelines, and optimal use cases. The physicians who recover the most are those who understand both strategies and deploy them strategically. In this guide, we will break down exactly how each process works, when to use each one, and how a dual-strategy approach can unlock recovery dollars that a single-track strategy would miss entirely.
Why this matters: the two processes reach different claims, not the same claims by different routes. Federal IDR covers items and services under the No Surprises Act from 1 January 2022 forward. An ERISA appeal reaches employer-sponsored plan claims outside those bounds, including older ones, on deadlines set by the plan document rather than by the Act. A practice that has pursued neither usually has claims in both categories — and which category a claim falls into is a question with a right answer, not a matter of strategy preference. We are not going to quote you an uplift percentage for using both: we have no substantiated figure for that, and neither does anyone else who quotes you one.
IDR (Independent Dispute Resolution): The No Surprises Act Weapon
What It Is
Independent Dispute Resolution is a federal arbitration mechanism created by the No Surprises Act, which took effect on January 1, 2022. When an out-of-network provider and an insurance company cannot agree on a fair payment amount, either party can initiate IDR—a process where a certified, independent third-party arbitrator examines the evidence from both sides and issues a binding payment determination.
The process uses a "baseball-style" arbitration model: each party submits a proposed payment amount along with supporting evidence, and the IDR entity must choose one offer or the other. There is no splitting the difference. This all-or-nothing structure incentivizes both parties to submit reasonable offers, but in practice, it has proven remarkably favorable to providers.
When to Use IDR
IDR is specifically designed for disputes involving:
- Out-of-network emergency services—the single largest category of IDR-eligible claims, including emergency medicine, anesthesiology, and radiology performed in the ED
- Ancillary services at in-network facilities—when an out-of-network provider delivers care at a facility that is in the patient's network (pathology, assistant surgery, neonatology, etc.)
- Air ambulance services provided by out-of-network operators
- Non-emergency services where the patient did not have meaningful choice of provider
The IDR Process: Step by Step
Open Negotiation Period (30 business days): After the provider receives an initial payment or denial, both parties have 30 business days to negotiate directly. Most insurers use delay tactics during this period, making resolution rare.
IDR Initiation: Either party initiates IDR through the federal portal. A $15 administrative fee is required from each party at filing — down from $115 for disputes initiated on or after June 11, 2026.
IDR Initiation & Entity Selection (4 business days): The initiating party has 4 business days to begin the IDR process. Both parties then jointly select (or are assigned) a certified IDR entity—an independent arbitrator approved by CMS.
Submission Window (10 days): Each party submits their proposed payment amount and supporting documentation, including evidence of the Qualifying Payment Amount (QPA), market rates, provider training, case complexity, and patient acuity.
Determination (30 business days): The certified IDR entity reviews both submissions and selects one party's offer as the final, binding amount. The losing party pays the IDR entity's fees.
IDR by the Numbers
- Cost: $15 administrative fee per party since June 11, 2026 (down from $115), plus the certified IDR entity's fee, which is set within a range the Departments publish annually and is paid by the non-prevailing party
- Timeline: set by statute — 30 business days of open negotiation, a 4-business-day window to initiate, and 30 business days for the certified IDR entity to decide, with payment due within 30 calendar days of the determination
- Outcomes: the provider side prevailed in ~85% of payment determinations in 2024 (CMS) — determinations, not disputes: about 19% of disputes initiated that year were found ineligible and never reached one
- Award range: the median prevailing offer sat above the plan's QPA — from 1.73× on claims of $10,000 and above to 5.53× on claims under $100 (CMS, Q4 2024), and higher still in some specialty categories
- Volume: certified IDR entities closed 1,371,862 disputes in 2024 against 311,863 in 2023 — 4.4 times as many — and issued 1,047,575 payment determinations (CMS)
IDR Limitations
Despite its power, IDR has important constraints:
- Effective date cutoff: Only claims with dates of service on or after January 1, 2022 are eligible—leaving years of prior underpayments unaddressable through this channel
- Service restrictions: Not all out-of-network claims qualify; the service must fall into specific categories defined by the No Surprises Act
- QPA anchoring: While arbitrators consider multiple factors, insurers often submit artificially low QPAs to anchor the discussion. Strong documentation and data-driven analysis are essential to counter this
- Batching rules: CMS limits how claims can be batched together, sometimes requiring multiple separate filings for what might logically be a single dispute
ERISA Appeals: The Hidden Powerhouse
What It Is
The Employee Retirement Income Security Act (ERISA) is a federal law enacted in 1974 that governs employer-sponsored benefit plans, including the health insurance plans provided by most mid-to-large employers. ERISA covers an estimated 180 million Americans—roughly half the country's population—making it one of the most broadly applicable federal statutes in healthcare.
Under ERISA, plan participants and their healthcare providers have the right to appeal benefit denials and underpayments through a structured process that can ultimately reach federal court. Unlike IDR, which was designed specifically for the post-No Surprises Act era, ERISA appeals draw on decades of case law and regulatory precedent.
When to Use ERISA Appeals
ERISA appeals are the right tool when:
- The patient is covered by an employer-sponsored health plan—this covers the majority of commercially insured patients in the United States
- The claim was denied or underpaid based on the plan's determination of usual and customary rates, medical necessity, or benefit limitations
- Balance billing disputes where the insurer's payment was insufficient and the plan language supports a higher payment
- Pre-2022 claims that fall outside the IDR eligibility window but are within the plan's or state's lookback period
- Claims not eligible for IDR, including many non-emergency out-of-network services and situations where the No Surprises Act does not apply
The ERISA Appeals Process: Step by Step
Internal Appeal (First Level): Submit a formal appeal to the insurance company with supporting documentation, clinical records, and legal arguments based on the plan's own language. The plan must respond on the timetable ERISA's claims-procedure regulation sets for the type of claim (29 CFR 2560.503-1), which for post-service claims runs to 60 days, or two 30-day stages where the plan operates a two-level appeal.
Internal Appeal (Second Level): Many plans require a second-level internal appeal before proceeding to external review. This provides an additional opportunity to present evidence and arguments.
External Review: After exhausting internal appeals, the case goes to an independent external reviewer (IRO). This reviewer examines the medical record, plan language, and applicable standards. Their decision is binding on the insurer.
Federal Court (if needed): If the external review is unfavorable, or if procedural violations occurred, the provider can file suit in federal court under ERISA Section 502(a). Courts apply a deferential standard of review but can overturn arbitrary or capricious decisions.
ERISA by the Numbers
- Cost: Generally no filing fees for internal appeals and external review. Federal court involves standard litigation costs.
- Timeline: set by the plan document and ERISA's claims-procedure regulation rather than by a single federal clock; litigation, if it comes to that, is longer again
- Outcomes: no federal agency publishes an aggregate success rate for ERISA external review the way CMS does for IDR, so treat any single number you are quoted for it — including by us — with suspicion. Outcomes turn on the plan document and the quality of the administrative record
- Award Range: Full billed charges are possible when plan language supports it—not limited to a QPA multiple
- Lookback period: set by the plan document and the applicable limitations period rather than by a single federal rule — which is why it can reach claims predating the No Surprises Act, and why it has to be read off your own plan rather than assumed
The Key ERISA Advantage: Reaching Back in Time
Perhaps the most powerful aspect of ERISA appeals is the ability to recover claims that predate January 1, 2022. While IDR only applies to claims after the No Surprises Act took effect, ERISA's lookback window can reach 3, 4, 5, or even 6 years into the past depending on the state and the specific plan terms.
For a busy out-of-network practice, this can represent a massive untapped pool of recoverable revenue. Consider: if your practice has been systematically underpaid by 40–60% on employer-sponsored plan claims for the past five years, the cumulative underpayment could easily reach six or seven figures.
Why this matters for the calendar. Federal IDR reaches claims from 1 January 2022 forward. Anything before that date is outside the process entirely, however strong the case — and for employer-sponsored plans, an ERISA appeal is the remaining route, governed by the plan's own deadlines rather than the Act's. A practice that has never looked at its pre-2022 claims has not necessarily lost them; it has simply never asked the question in the forum that can still hear it.
Results shown are illustrative examples and vary based on claim specifics, payer behavior, and documentation quality. Past outcomes do not guarantee future results.
ERISA Limitations
- Plan type restriction: Only applies to employer-sponsored plans governed by ERISA—not individual marketplace plans, Medicare, Medicaid, or government employee plans (these fall under different federal or state rules)
- Longer timelines: The multi-step appeals process takes significantly longer than IDR
- Documentation burden: Strong legal arguments tied to specific plan language are essential; generic appeals rarely succeed
- Assignment of benefits: Providers must have proper assignment of benefits from the patient, or anti-assignment clauses may block standing
Head-to-Head Comparison
The following table summarizes the critical differences between IDR and ERISA appeals to help you determine which strategy—or combination of strategies—fits your practice:
| Factor | IDR (No Surprises Act) | ERISA Appeals |
|---|---|---|
| Eligible Claims | OON emergency, ancillary at in-network facilities, air ambulance | Any employer-sponsored plan claim (denial, underpayment, balance billing) |
| Timeline | 30 + 4 + 30 business days by statute | Set by the plan document and ERISA's claims-procedure rule |
| Cost to Provider | $15 admin (from 6/11/2026) + entity fee within the Departments' published range, paid by the non-prevailing party | Generally free (internal + external review) |
| Win Rate | ~85% | Not published in aggregate |
| Award Basis | QPA + additional factors (complexity, training, market rates) | Plan terms + medical necessity + UCR data |
| Typical Award | 1.73×–5.53× QPA by claim size | Full billed charges possible |
| Lookback Period | Jan 1, 2022 onward only | Per plan document and the applicable limitations period |
| Decision Type | Binding (baseball arbitration) | Binding at external review; federal court available |
| Population Covered | All commercially insured patients (for eligible services) | ~180M Americans on employer-sponsored plans |
| Best For | Fast resolution, high win rate, recent OON claims | Older claims, plan language disputes, larger total recovery |
When to Choose IDR
IDR is the optimal strategy when several conditions align:
Clear OON Emergency Claims
- Patient presented to the ED and you provided out-of-network services
- Insurer paid significantly below your billed charges
- Date of service is January 1, 2022 or later
- You have strong documentation of case complexity, patient acuity, and market rates
Cash Flow Priority
- You need a decision on the statutory clock rather than on the plan's own appeal timetable
- Your billed charges significantly exceed the QPA (2x or more)
- You want to batch multiple claims for efficient processing
- The ~85% provider success rate on decided disputes (CMS, 2024) provides strong risk-adjusted expected value
IDR is particularly powerful for emergency medicine physicians, anesthesiologists, radiologists, and pathologists who frequently provide out-of-network services at in-network facilities. These providers often have the strongest IDR cases because their services fall squarely within the No Surprises Act's qualifying categories.
When to Choose ERISA Appeals
ERISA appeals become the preferred strategy under different circumstances:
Employer Plan Underpayments
- The patient's coverage comes from an employer-sponsored plan
- The plan language supports payment at a higher rate than what was reimbursed
- Claims date back before January 2022 (outside IDR window)
- You have systematic underpayment across many claims from the same payer
Large Historical Underpayments
- You have years of underpaid claims from a single employer plan, including claims predating 2022
- The aggregate underpayment is significant (six figures or more)
- Plan language or UCR data supports full billed charges
- The claims are not eligible for IDR (pre-2022 or non-qualifying services)
ERISA appeals are particularly valuable for practices that have been operating out-of-network for many years and have accumulated a large backlog of underpaid claims. Because an employer plan's lookback can reach claims the Act cannot, a practice with older out-of-network volume may have more at stake there than in the federal process, even though individual IDR cases may resolve faster.
The Dual-Strategy Approach: Why Not Both?
Here is the insight that separates sophisticated revenue recovery from basic claims management: IDR and ERISA appeals are not mutually exclusive. They target different claim populations with minimal overlap, making them ideal for simultaneous deployment.
The math is straightforward: If your practice has been underpaid on both IDR-eligible claims (post-2022) and ERISA-eligible claims (pre-2022 employer plans), pursuing only one channel leaves the other untouched. A dual-strategy approach captures revenue from both pools.
At Proprius Recovery, we routinely deploy both strategies in parallel for our clients. Here is how the dual approach typically works:
- Audit and classify: We analyze your entire claims history to identify which claims qualify for IDR, which qualify for ERISA appeals, and which may qualify for both or other state-level remedies
- Prioritize by expected value: High-value IDR cases are fast-tracked for immediate filing, while ERISA appeals are built on thorough plan language analysis and legal argumentation
- Parallel execution: IDR filings and ERISA appeals proceed simultaneously—there is no need to wait for one to resolve before starting the other
- Compound recovery: As IDR wins come in (on the statutory clock — 30 business days of negotiation, 4 to initiate, 30 for the determination), they generate revenue while any employer-plan appeals run on their own timetable over the following months
Why the two run together. The dividing line is mostly the calendar and the plan type. Federal IDR reaches claims from 1 January 2022 forward, when the No Surprises Act took effect, and only items and services the Act covers. ERISA appeals reach employer-sponsored plan claims that fall outside those bounds, including older ones, subject to the plan's own deadlines. A practice that has never pursued either usually has claims in both categories, and sorting which is which is the first piece of work — not a strategy choice so much as a filing question with a right answer.
Decision Framework: Choosing Your Path
Use this decision framework to determine the right strategy for each claim or group of claims in your portfolio:
Claim Recovery Decision Framework
Yes → Pursue IDR. This is the fastest path with the highest win rate (~85%). File through the federal IDR portal after the 30-day negotiation period.
Yes → ERISA appeals are available. Check if the plan language supports a higher payment. Especially valuable for pre-2022 claims outside the IDR window.
Some post-2022 employer plan claims may qualify for both. In these cases, start with IDR for speed. If IDR does not fully resolve the underpayment, ERISA appeals can address the remaining gap.
Yes → Deploy the dual strategy. File IDR for qualifying recent claims while simultaneously building ERISA appeals for older claims. This maximizes total recovery and smooths cash flow.
Get a free analysis. Our team at Proprius Recovery will audit your claims, classify each one by the optimal recovery channel, and set out which route applies to each claim and what the deadlines are, at no upfront cost. See what we charge and what the federal process charges.
Common Mistakes That Leave Money on the Table
These are the errors that most often cost a claim, and each of them is a rule you can check for yourself before anything is filed:
- Ignoring pre-2022 claims entirely. Many providers assume that claims older than a year or two are lost forever. That is true of federal IDR, which reaches nothing before 1 January 2022. It is not automatically true of an employer-sponsored plan claim, where the deadline is set by the plan document and the applicable limitations period rather than by the Act.
- Filing IDR without proper documentation. The ~85% figure is the share of payment determinations decided for the provider side, and it is an average across all of them. Providers who submit thin documentation with generic arguments see much lower success. Strong IDR filings include detailed case complexity analysis, market rate data, provider qualifications, and patient acuity evidence.
- Not reading the plan language. ERISA appeals succeed or fail based on the specific terms of the employer's plan document. A generic appeal citing "usual and customary rates" without reference to the plan's actual payment methodology is far less persuasive than one that cites specific plan provisions.
- Missing filing deadlines. Both IDR and ERISA have strict timing requirements. IDR requires initiation within the regulatory window after receiving payment; ERISA internal appeals typically must be filed within 180 days of the adverse determination. Missing these windows forfeits your right to pursue recovery.
- Treating all underpayments the same. A $500 underpayment and a $15,000 underpayment require different strategic approaches. High-value claims may warrant more extensive documentation and more aggressive pursuit, while lower-value claims benefit from efficient batching.
Building Your Recovery Strategy
The world of medical revenue recovery has fundamentally changed since the No Surprises Act introduced IDR in 2022. For the first time, out-of-network providers have a fast, federally mandated arbitration process with a strong track record of favorable outcomes. Combined with the existing power of ERISA appeals for employer-sponsored plans, physicians now have an unprecedented toolkit for fighting insurance underpayments.
The question is no longer whether to pursue recovery—it is how to do it strategically. The answer, for most practices, involves both IDR and ERISA:
- IDR for recent OON emergency and ancillary claims—fast resolution, high win rate, strong median awards
- ERISA for employer plan claims spanning multiple years—larger total recovery, ability to reach back in time, full billed charges possible
- Dual strategy for maximum total recovery—parallel execution, complementary claim populations, compounding returns
Every month you wait to act is another month of underpayments that may slip past their lookback window. The claims you can recover today may not be recoverable tomorrow.