If you’ve ever stared at a remittance advice trying to figure out why a claim got paid the way it did, you know the feeling. Rows of codes, no context, and a payer that’s technically told you everything while explaining nothing. Since the No Surprises Act (NSA) took effect, there’s been a specific batch of these codes meant to help—Remittance Advice Remark Codes, or RARCs, tied specifically to NSA claims. Up until now, though, using them has mostly been optional. Payers could use them, but didn’t have to.
That’s changing. On July 17, 2026, CMS released new guidance implementing the Federal Independent Dispute Resolution Operations final rules published back on June 4. The short version: plans and issuers will soon be required to use a specific, defined set of RARCs on remittance advice for NSA claims—not just encouraged to.
The Timeline
Three dates matter here, and they’re not all the same date:
- August 3, 2026—this is when the underlying final regulations take effect.
- November 1, 2026—this is when the actual RARC code table in the new guidance goes live.
- January 1, 2027—this is the one to circle. The requirement to use these codes applies to items and services furnished on or after this date.
So, the rule exists sooner, but it doesn’t apply to claims for services delivered until January 1, 2027.
A Smaller, More Specific Set of Codes
Here’s the part worth paying attention to: this isn’t just “the old 2022 codes, now mandatory.” The new required list is narrower, and it’s organized entirely around the payment itself rather than around which NSA scenario applies. There are nine required codes, split into four groups.
Initial payment:
- N871—the initial payment was based on a specified state law. Need to use the State IDR process. Not eligible for Federal IDR.
- N877—the initial payment reflects the lesser of the qualifying payment amount or the billed charge. This one is Federal IDR-eligible, but only after the open negotiation period runs its course.
Denial of payment:
- N876—a formal denial, the service is covered, but no payment was made, and the amount is based on the qualifying payment amount or billed charge. IDR-eligible after open negotiation.
- N944—a new code. Same denial scenario, but the amount was based on a specified state law or an All-Payer Model Agreement instead. State eligible. Not Federal IDR-eligible.
Final payment:
- N872—final payment based on a specified state law. Not Federal IDR-eligible.
- N873—final payment based on an All-Payer Model Agreement. State eligible. Not Federal IDR-eligible.
- N874—final payment reached through open negotiation. Not IDR-eligible (makes sense—the parties already agreed).
- N875—final payment equals the amount a certified IDR entity determined. Not IDR-eligible (also makes sense—that determination is generally binding).
Not subject to surprise billing:
- N943—another new one. Used when the item or service simply isn’t subject to NSA surprise billing protections at all, often because valid notice-and-consent requirements were met. Not IDR-eligible.
Notice what’s missing compared to the old 2022 list: the codes that used to just flag which NSA scenario applied (N864, N865, N866) and the ones that explained cost-sharing math (N862, N867–N870) aren’t part of this required set. Neither are the notice-and-consent codes N878 and N879—N943 effectively absorbs that idea now. Plans and issuers aren’t necessarily barred from still using the old codes for extra context, but going forward, these nine are the ones that count for compliance.
Why the IDR-Eligibility Column Is the Real Headline
Every code in the new table comes with an explicit yes-or-no answer to one question: can a dispute over this payment go to the Federal IDR process? That’s a genuinely useful thing to have spelled out in black and white, because it tells a provider or facility, right on the remittance advice, whether their next move is to accept the payment, request an extension, or start the clock on open negotiation.
Worth noting: the plan or issuer’s answer isn’t the final word. The guidance is explicit that certified IDR entities are the ones who ultimately decide eligibility. If your read of a claim doesn’t match the code the payer used, you’re not stuck—you can still initiate the Federal IDR process after open negotiation ends and let the IDR entity sort it out.
Where These Codes Actually Have to Show Up
CMS also spelled out exactly where the codes need to live, which matters if you’re on the compliance or systems side:
- On electronic remittance advice (the ASC X12 835 standard), the RARC must go in the LQ segment within Loop 2110 for each line item.
- On paper remittance advice, the RARC must appear within the document itself, tied clearly to the relevant line item—not mailed separately or referenced elsewhere.
What Happens If a Payer Doesn’t Comply
This is the part providers should actually care about. If a plan or issuer doesn’t follow these requirements, you’re not just out of luck. You still retain the right to initiate open negotiation within 30 days of getting the initial payment or denial notice. And if the payer’s noncompliance actually leaves you without enough information to hit the open negotiation deadline, you can request an extension by emailing FederalIDRQuestions@cms.hhs.gov.
Compliance concerns can also be reported directly to the No Surprises Help Desk at 1-800-985-3059, or filed as a complaint through CMS’s provider resources page for plans and issuers.
The Takeaway
This isn’t a footnote update—it’s CMS closing a real gap. For nearly four years, RARC use on NSA claims has been inconsistent because it was never required. Starting with services furnished January 1, 2027, that inconsistency has a deadline. If you’re in billing, claims follow-up, or revenue cycle work touching out-of-network claims, it’s worth updating your reference sheets now rather than in December.
A cleaner code doesn’t recover revenue on its own—someone still has to catch the miscoded denial, question the state-law payment that should’ve been QPA-based, and know when to push a dispute into Federal or State IDR. That’s the work Aspirion’s out-of-network recovery team handles every day. If this update has you wondering how many of your NSA claims are sitting on the table, let’s talk.
