A new C-code, a new denial pattern
An ASC in Texas billed a knee arthroscopy with an iovera° cryoanalgesia treatment in March 2026. The surgery paid clean. The non-opioid pain treatment, billed separately for the first time under the NOPAIN Act, came back denied. The billing manager's first instinct was to appeal it as a medical necessity issue. It wasn't. The claim had gone out with the old packaged code instead of the new C-code CMS assigned to iovera° under the Act.
That single miscode cost the facility roughly $1,900 in separate reimbursement it was newly entitled to, on a claim that would have paid automatically eighteen months earlier when the drug was still bundled into the surgical fee.
This is happening across ASCs right now, and most billing teams don't know why.
What the NOPAIN Act actually changed
The Non-Opioids Prevent Addiction In the Nation (NOPAIN) Act went into effect January 1, 2025. Before it, non-opioid pain management products used during ASC and hospital outpatient department (HOPD) procedures, things like EXPAREL (a long-acting local anesthetic), iovera° (cryoanalgesia), and certain infusion pump systems, were packaged into the surgical bundle. The facility absorbed the cost as part of the procedure's flat fee. There was no separate line item, no separate reimbursement, and critically, no separate claim to deny.
The NOPAIN Act unbundled qualifying non-opioid products. Medicare now reimburses them separately, under their own HCPCS C-codes, on top of the primary procedure payment. For ASCs that use these products regularly, particularly ortho and pain management facilities trying to reduce post-operative opioid exposure, this is real incremental revenue. It's also a new claim type, with its own rules, its own documentation requirements, and its own denial risk.
Most ASC billing teams built their claim submission and denial-prevention workflows around the old bundled model. The Act didn't just add a payment opportunity. It added an entirely new failure surface that nobody was watching for.
The four failure points
1. Payer mismatch
The NOPAIN Act is a Medicare mandate. It does not apply to commercial payers. Commercial insurers generally still bundle non-opioid drug costs into the procedure fee, or require them to be billed through separate DME channels entirely. Billing teams that apply the new C-codes to commercial claims out of habit, because the same drug was used on a Medicare patient the day before, get immediate denials. This is the single most common failure point we see, because it's a workflow habit problem, not a knowledge gap. The staff know the rule. The claim scrubber doesn't enforce it.
2. Missing or incorrect HCPCS C-codes
CMS assigns specific C-codes to qualifying non-opioid products, and these codes update quarterly through the OPPS Addendum B. iovera°, for example, maps to C9809. If an ASC's chargemaster still points to the old packaged procedure code, or hasn't been updated to reflect a code change CMS issued that quarter, the claim either denies outright or pays at the wrong rate. Chargemasters are usually maintained by whoever owns coding, often a part-time function at a facility this size, and quarterly CMS updates are easy to miss without a standing process to catch them.
3. Documentation gaps
Medical necessity denials on NOPAIN claims almost always trace back to physician documentation that doesn't explicitly state two things: that the non-opioid treatment was medically necessary as a post-operative pain alternative, and that it does not act on opioid receptors. Generic operative notes that say "pain managed with iovera°" without that specific framing trigger clinical validation denials, because the payer's algorithm is looking for language that distinguishes the treatment from a bundled or a standard-of-care intervention.
4. The 18% payment cap
Separate reimbursement under the Act is capped at 18% of the HOPD fee schedule amount for the primary procedure the drug was previously packaged with. Claims that exceed this threshold, whether because of billing error or because multiple non-opioid products were used on one case, get flagged for partial payment or full denial. This cap is not intuitive, and it's not something most billing staff would think to check before submission.
A decision tree for claim routing
Before submitting a claim with a non-opioid pain product, the routing logic should run through four checks:
Is the payer Medicare or Medicare-adjacent? If not, the NOPAIN C-codes don't apply, route to standard bundled billing.
Does the chargemaster reflect the current-quarter CMS C-code for this specific product? If the code hasn't been verified against this quarter's OPPS Addendum B, hold the claim for a coding review.
Does the operative note explicitly document medical necessity language, non-opioid mechanism, and post-operative pain indication? If not, route back to the physician for an addendum before submission.
Does the calculated separate payment fall within 18% of the HOPD fee schedule for the primary procedure? If it's close to or over the threshold, flag for manual review rather than auto-submitting.
Facilities that build this into their claim scrubber logic, rather than relying on billers to remember it case by case, see meaningfully fewer NOPAIN-related denials. Facilities that don't are functionally re-learning this the hard way, one denied claim at a time.
A quarterly chargemaster audit checklist
Because CMS updates C-codes quarterly, a static chargemaster becomes stale fast. A minimal audit process should check, every quarter: whether any new non-opioid products were added to the OPPS Addendum B qualifying list, whether existing C-codes changed, whether the 18% cap calculation basis shifted with fee schedule updates, and whether commercial payer contracts have been reviewed for parallel non-opioid billing policies (some commercial payers are beginning to follow Medicare's lead, though most have not).
This is the same operational discipline ASCs already apply to annual CPT code updates. NOPAIN just adds a second, faster-moving cycle to track.
FAQs
Does the NOPAIN Act apply to commercial payers? No. It is a Medicare mandate only. Commercial payers generally still bundle non-opioid costs or require separate DME billing. Applying the new C-codes to commercial claims will result in immediate denials.
What are the new HCPCS C-codes for non-opioid treatments? CMS established specific C-codes for qualifying products, for example C9809 for iovera°. Check the latest CMS OPPS Addendum B for the full list, since these update quarterly.
What documentation is required to avoid clinical validation denials? The physician must explicitly document that the non-opioid treatment is medically necessary to reduce post-operative pain and that it does not act on opioid receptors. Generic pain management notes are insufficient.
What is the 18% payment cap and how does it work? Separate payment for the non-opioid treatment cannot exceed 18% of the HOPD fee schedule amount for the primary procedure it was previously packaged with. Claims exceeding this threshold get partial payments or flags.
How often should we audit our chargemaster for NOPAIN compliance? Quarterly, at minimum, aligned with CMS OPPS updates. Any time CMS releases new C-codes or modifies existing ones, the chargemaster must be updated before the next billing cycle.
We're an ASC, does this apply to us or only HOPDs? Both. The Act covers Ambulatory Surgery Centers and Hospital Outpatient Departments equally.
The takeaway
The NOPAIN Act is a rare case where a regulatory change adds revenue and adds risk in the same motion. The revenue is real. So is the exposure, and it shows up as a specific, traceable pattern: payer mismatch, stale chargemaster codes, thin documentation, and cap breaches. None of these are clinical judgment calls. They're workflow gaps.
If your facility started billing non-opioid pain products separately in the last year and your denial rate on those specific claims looks higher than your baseline, that's not noise. It's one of these four causes, and it's worth tracing before the next quarterly CMS update adds a fifth.
For the broader pattern of claims that pay less than they should without triggering a denial, see implant billing revenue leakage in ortho ASCs. For how a similarly generic appeal fails to get read, see common gaps in healthcare appeal workflows. For the operational load this kind of tracking adds to an already thin team, see what RCM staff turnover actually costs.
Sources: CMS ASC Payment System, CY 2025 OPPS/ASC Final Rule.