ER Underpayment Recovery: Spot, Dispute and Collect

How do I know if an ER claim was underpaid?

An ER claim is underpaid when the amount the payer allowed is lower than the benchmark that governs that claim. Which benchmark governs depends on whether the payer is in network with you and on the program or plan type.

Two other tests catch problems that a rate comparison misses. Was the claim paid at the code you billed, and was every line either paid or explained? Both come up below.

This guide is about money after a claim has been paid. For the front half of the cycle, see our guide to the No Surprises Act for ER groups. For the coding that sets the level you bill, see our ED coding and documentation guide.

What does the ERA tell me about a payment?

The ERA (electronic remittance advice) is the payer's line-by-line explanation of a payment, sent in the X12 835 format. HIPAA transaction rules adopt that format for health care claim payment and advice at 45 CFR 162.1602, which is why every payer that pays electronically can send one.

For each claim line the remit shows the amount billed, the amount paid and a list of adjustments. Each adjustment carries a group code and a CARC (claim adjustment reason code). X12 says group codes assign responsibility: CO is contractual obligation, PR is patient responsibility, OA is other adjustment and PI is payer initiated reduction. The CARC gives the reason, and a RARC remark code can add detail.

CARC 45 versus a real underpayment

X12 words CARC 45 as "Charge exceeds fee schedule/maximum allowable or contracted/legislated fee arrangement" and says to use it only with group codes PR or CO. A CO-45 adjustment is the normal write-off between your charge and the payer's allowed amount. It tells you the payer applied a fee arrangement. It does not tell you the arrangement was applied correctly. The CO-45 code page covers the code on its own.

A real underpayment hides inside a CO-45 when the schedule the payer applied is lower than the one in your contract, or when the right schedule was applied to the wrong code. You can only see it by rebuilding the allowed amount yourself.

A common way to calculate the allowed amount on a line is the paid amount plus every patient responsibility amount on that line, such as deductible, coinsurance and copay. Compare that figure with the contracted rate for the same code, modifier and units. The difference is the variance.

How do I run an ERA variance report?

A variance report compares what each remit line allowed with what the contract says it should have allowed, and lists the lines that fall short. Run it on every payer remit batch, not once a quarter, because most payer clocks are short.

The pattern matters more than the single line. If the same payer shortfalls the same code on most claims, a fee schedule load error is the likely cause, and one corrected schedule can fix every future claim.

What if the insurer paid zero on part of the claim?

A zero-paid line is not a final answer. Read the CARC first, because it says whether the payer treated the line as bundled, not covered, unsupported by the record or downcoded.

For commercial out-of-network emergency claims, federal rules give you more to work with. Under 45 CFR 149.110(b)(1) the plan must cover emergency services without prior authorization, even when they are out of network. Under 149.110(b)(4) it may not limit what counts as an emergency medical condition solely on the basis of diagnosis codes. A denial that rests on a missing authorization or on the diagnosis code alone deserves a written challenge.

A zero payment also starts the dispute clock. The open negotiation notice under 45 CFR 149.510(b)(1) asks for the initial payment amount and says to enter $0 if payment is denied. The open negotiation page has the window; do not wait on a second remit before you count it.

How do I handle stealth downgrades of ER levels?

A stealth downgrade is a payment at a lower E/M level than you billed, such as 99285 paid as 99284, without a clear denial. Because the line is paid, it passes a total-paid report. Only a comparison of the code billed with the code paid finds it.

Add a code-billed versus code-paid column to your variance report and flag every mismatch. Look for CARC 150 and for CARC 57, which X12 words as payment denied or reduced because the payer deems the information submitted does not support this level of service, this many services, this length of service, this dosage or this day's supply.

For commercial out-of-network claims the payer has a disclosure duty. When a QPA is based on a downcoded service code or modifier, 45 CFR 149.140(d)(1)(ii) requires a statement that the code or modifier was downcoded, an explanation of why, and the amount the QPA would have been without the downcode. If the remit shows a lower code and no such statement, ask for it in writing.

To answer a downgrade:

1. Pull the chart and level the visit yourself from the medical decision making, using the method in our ED coding and documentation guide.
2. Read the payer's provider manual and your contract for any level review or downcoding policy.
3. Appeal with the record. Quote the problems addressed, the data reviewed and the risk decisions in the clinician's own words, and attach the pages.

If the visit was billed on a hospital facility claim, the facility level follows the hospital's own written guideline instead of the professional MDM method. The ED facility level coding rule explains the difference, so keep the two appeals separate.

How do I compare a payment to the QPA?

Compare the initial payment plus the patient's cost sharing with the QPA the payer sent on the remit. The QPA is the payer's median in-network rate, and 45 CFR 149.140(d)(1) requires the plan to give it to you in writing with each initial payment or notice of denial when the recognized amount is the QPA or the billed amount.

The arithmetic follows the rule. In a state with no specified state law, 45 CFR 149.30 sets the recognized amount at the lesser of the QPA or the billed amount, and 149.110(b)(3)(iii) bases patient cost sharing on that recognized amount. The plan's total payment is then the out-of-network rate minus the cost sharing and minus the initial payment already made, under 149.110(b)(3)(iv)(B).

The initial payment is not the final rate. The definition of out-of-network rate in 45 CFR 149.30 counts an amount the parties agree on, including an initial payment they agree to keep, and otherwise the amount an IDR entity decides. So an initial payment you leave unchallenged can become the rate, which is a reason to compare every payment, not only the large ones.

The QPA page explains how the payer calculates it and what to request. The federal IDR page lists the other factors an entity weighs, so a payment equal to the QPA is a starting point for your offer and not a reason to close the file.

Which underpaid claims are worth disputing?

Dispute a claim when a route exists, the gap beats the cost of working it, the evidence is in hand and the clock is still open. Rank by total recoverable dollars for a payer and code together, not by single claims.

Many small gaps can still be worth the work when they repeat. The batching page states which claims may share one dispute, so read it before you group them.

Also separate underpayments from coding errors. If the payer's lower level is right on the chart, fix the documentation and coding process instead of disputing.

What is the process from underpayment to IDR?

The path runs from detection to a paid award in eight steps. The timing of each step is on the NSA pages linked below, so this list shows order and ownership, not days.

Our guide to the No Surprises Act for ER groups shows where this fits the wider cycle.

How do I dispute an underpayment, by payer type?

Match the route to the payer type before you write anything. Sending a Medicare Advantage claim to federal IDR, for example, wastes the clock.

For Original Medicare, the first fix for a simple error is a reopening. Under 42 CFR 405.980(c)(1) a party may request that the contractor reopen an initial determination within 1 year for any reason. A redetermination request must be filed within 120 calendar days from receipt of the notice under 42 CFR 405.942, and receipt is presumed 5 calendar days after the notice date unless there is evidence to the contrary.

This guide is general information and not legal advice. Have counsel review contract terms, state law questions and any plan with unusual language before you rely on a route.

What deadlines apply to underpayment disputes?

Several clocks run at once, and they start at different events. The table lists the ones this guide relies on. For the No Surprises Act windows, use the linked pages and the calculator instead of counting by hand.

Can I recover underpayments on old claims?

Sometimes, but the route narrows with age. Federal open negotiation starts from the date you received the initial payment or denial, so a claim whose window has passed cannot use it. Original Medicare allows reopening for any reason within 1 year. A contract, a payer's filing limits and state law may set other limits, and the timely filing limits by payer page lists the filing side. Have counsel read the contract before you chase a claim that is more than a year old.

What data do I need for an IDR submission?

Collect the open negotiation notice items on day one, because the same facts feed the IDR initiation. Section 149.510(b)(1)(ii) lists what the open negotiation notice must contain.

• Your legal business name, contact details and NPI, and the same for any third party acting for you with an attestation of authority
• The plan's legal business name, its registration number or an attestation that none appeared on the remit, and its contact details
• Dates of service, the date you received the initial payment or denial, the claim number, the service code, the state and the location
• Whether the service is an emergency service, and whether it is a professional or a facility-based service
• The initial payment amount, entered as $0 if payment was denied
• The QPA, if the remit gave one
• Your offer of an out-of-network rate for each item or service
• A statement that the notice and consent exception does not apply, and a statement that you were out of network on the date of service
• A copy of the remittance advice

For the IDR step, the IDR process page lists what CMS encourages parties to upload, including the full remit, proof that open negotiation started, the claim number, a complete EOB and the QPA. Redact patient health information first. Keep the chart, the contract termination or non-participation record and proof of claim receipt ready, because the plan can challenge out-of-network status.

How do state processes differ from federal IDR?

A state process replaces federal IDR when a specified state law sets the method for the total payment. CMS's applicability chart says federal IDR does not apply where a specified state law or an all-payer model agreement provides that method.

The same chart says federal IDR applies to self-insured employer plans in all states, except where the plan opted into a state law in a state that permits it, or an all-payer agreement applies. So two patients in one ER with different plan types can follow different routes. The chart notes that CMS's state information was current as of a stated date, so confirm the state's current law.

Check the plan type on the claim before you pick a route. Our state surprise billing laws page lists state processes, and the state pages in this site cover local detail.

How do I track underpayments by payer?

Track flagged dollars, worked dollars and recovered dollars by payer and by code each month. A tracker that shows only totals hides the payer behavior you most need to see.

For out-of-network disputes we measure performance by decision win rate, award-to-offer ratio, reimbursement recovered and collections, using verified case-level data. Use the same four measures in your own tracker so results can be compared payer to payer.

How long does recovery take?

There is no fixed length. A contract appeal runs on the payer's appeal timeline, a Medicare reopening or redetermination on the MAC's, and a federal dispute on the windows set in 45 CFR 149.510.

Add up the open negotiation, IDR start, selection, offer and decision windows on the NSA pages and the total reaches months before any payment is due, since the rule counts most of them in business days. Payment after a decision is due within a set number of calendar days, which the IDR page states. Plan for that span when you forecast cash, and start counting on the day the remit arrives, not the day someone reads it.

How does Nucleus Align handle ER underpayment recovery?

We recover the revenue insurers underpaid you under the No Surprises Act. For out-of-network claims we run the work end to end: eligibility assessment, open negotiation, dispute submissions, deadline management, documentation validation and outcome tracking, under federal IDR and applicable state pathways, including Texas TDI.

Our controls are eligibility verification, deadline tracking, accurate documentation, required fees paid on time, and jurisdiction-specific compliance checks across open negotiation, IDR and TDI workflows. The out-of-network billing and IDR service page describes that work, and our accounts receivable service covers the older balances.

If you want a second look at the remits you already hold, book a call.