HCPCS code C1878 – Material for vocal cord medialization

Key takeaways

HCPCS Code C1878 is a C-series Level II code for synthetic implantable material used in vocal cord medialization.

The code applies only in hospital outpatient settings under OPPS, never in a physician office or on a professional claim.

C1878 carries pass-through device status, so CMS pays for it separately from the procedure’s Ambulatory Payment Classification bundle.

C1878 is a device code, so it is always reported alongside a CPT procedure code such as 31591 for thyroplasty.

Pabau’s claims tools help outpatient billing teams pair device codes with procedure codes before submission.

HCPCS Code C1878: Overview and official description

HCPCS Code C1878 describes synthetic, implantable material for vocal cord medialization. That is the full official long description held by the Centers for Medicare and Medicaid Services (CMS) in the HCPCS Level II code set. The table below summarizes the core code metadata.

C-codes are temporary codes that CMS created for the hospital outpatient prospective payment system. They are not used in physician office or professional billing. Check the effective and termination dates against the CMS HCPCS Level II update files before you submit. Pass-through status and code validity can change with each OPPS final rule.

What does C1878 cover? Clinical context of vocal cord medialization

C1878 covers the synthetic implantable material used in a vocal cord medialization procedure, not the surgical work itself. Knowing how the procedure works clarifies why the device code sits apart from the CPT procedure code.

Vocal cord medialization treats unilateral vocal cord paralysis, where one vocal fold cannot move toward the midline during phonation. Patients usually present with a weak, breathy voice and a risk of aspiration. The standard surgical approach is thyroplasty, also called laryngeal framework surgery or type I thyroplasty. The surgeon opens a window in the thyroid cartilage and inserts a synthetic implant that pushes the paralyzed cord toward the midline. That implant is what C1878 describes.

Key clinical indications that may support a C1878 claim include:

• Unilateral vocal cord paralysis following thyroidectomy, neck dissection, or thoracic surgery involving the recurrent laryngeal nerve
• Vocal cord paralysis due to central neurological causes such as stroke or tumor
• Vocal fold atrophy or bowing in appropriate surgical candidates
• Aspiration secondary to glottic incompetence requiring medialization for airway protection

The patient record for these cases should document the functional deficit, the surgeon’s assessment, and the decision to proceed with a synthetic implant. That documentation is the foundation of the medical necessity argument for C1878 on the claim.

Billing and coverage: How to report C1878

Correct claim submission for C1878 rests on the OPPS billing framework, the applicable settings, and the pass-through device designation. That designation makes the code behave differently from most supply codes.

C1878 as a pass-through device code under OPPS

Pass-through status under OPPS means CMS pays for C1878 separately from the Ambulatory Payment Classification (APC) that bundles the surgical procedure. Standard supply costs are folded into the APC payment and not billed separately. Pass-through device codes are the exception. The facility reports the code and receives an additional payment on top of the procedure APC.

CMS grants pass-through status when a device is new and represents a substantial clinical advance. The device must also cost enough that bundling it would significantly reduce the APC payment. Pass-through status is temporary. CMS reviews pass-through items each year in the OPPS final rule. A code moves from pass-through to packaged status once CMS has enough cost data to fold it into the APC.

• Billing placement: Report C1878 on the UB-04 (837I) claim alongside the surgical CPT code
• Revenue code: Typically revenue code 0278 for medical and surgical supplies, or whichever device revenue code your MAC requires
• Units: Report one unit per implant, and check the product’s billing instructions for multi-component implants
• Pass-through verification: Confirm current pass-through status in the CMS OPPS addenda before the service date

Commercial payers do not always follow Medicare OPPS rules for C-codes. Some require prior authorization for the implant separately from the surgical procedure, so confirm coverage before the case is scheduled. Checking upfront prevents post-service denials that are hard to reverse.

Applicable clinical settings for C1878

C1878 is a hospital outpatient code. The primary applicable setting is the hospital outpatient department (HOPD), where OPPS governs facility payment. CMS created the code for OPPS, and it is not used in the physician office or on professional claims (CMS-1500 / 837P).

Ambulatory surgical center (ASC) applicability needs separate verification. C-codes used under OPPS do not automatically map to the ASC payment system. CMS publishes a separate list of device-intensive procedures covered under that system. Check C1878’s current ASC status in the CMS ASC payment system files before billing it in an ASC. HOPD billing rules do not carry across by default.

When the facility builds its charge documentation for a thyroplasty case, it should record the facility type at the time of service. That record protects the claim if a payer questions whether the setting suited the code reported.

Fee schedule and Medicare reimbursement for C1878

Medicare pays for C1878 under the OPPS pass-through methodology. Pass-through status separates the device payment from the APC. The facility receives the APC payment for the procedure, plus a further payment for the device. That device payment is usually based on cost report data, or on a transitional pass-through amount set by CMS.

Dollar rates for C1878 vary by year, geographic wage index, and payer. The table below shows how pass-through payments are structured. Third-party fee schedule aggregators can lag behind annual OPPS final rule updates, so the CMS OPPS addenda are the authoritative source for hospital outpatient rates.

Good practice for thyroplasty cases is to pull the current OPPS addenda before each procedure. Confirm the device’s pass-through status, then document the implant cost in the medical record. CMS can request cost data during OPPS audits, and a facility that cannot produce it risks recoupment of the pass-through payment.

Related CPT and HCPCS procedure codes for thyroplasty

C1878 is a device code and does not capture the surgical work. The procedure is reported with a CPT code, and both codes belong to the same thyroplasty encounter. Building a claim template that carries both is the simplest safeguard here. Tighter claims management keeps the device code and the procedure code moving together on every claim.

The table below lists the CPT codes most often paired with C1878, with the clinical context for each.

One pairing is worth checking in any older coding guide you still rely on. CPT 31588 was deleted from the code set in 2017 and replaced by 31591, so a claim built on 31588 will not process. CPT 31587 is also easy to misread here, because it describes a cricoid split laryngoplasty without graft placement for subglottic stenosis.

The split between C1878 and the CPT code matters for compliance. The CPT captures the surgeon’s work and is reported on the professional claim by the physician. C1878 captures the implant device and is reported on the facility claim by the hospital. Putting both on the same claim type risks an unbundling error. The panel below shows how one encounter divides across the two forms.

ICD-10 diagnosis codes commonly linked to C1878

Medical necessity for C1878 rests on the diagnosis codes reported alongside it. The ICD-10 codes below appear most often on vocal cord medialization claims. The list is not exhaustive. Payer Local Coverage Determinations (LCDs) may name additional or alternative codes, and the clinical documentation has to support whichever code is chosen.

Always code to the highest specificity available. Laterality matters, so J38.02 and J38.01 beat J38.00 whenever the operative report names the affected cord. Unspecified codes invite payer requests for extra documentation and slow the claim down. Our ICD-10-CM code index lists the wider J38 range when the documented diagnosis falls outside the codes above.

Coding tips and common billing mistakes

Denials on C1878 claims cluster around a few specific errors. The guidance below covers the ones that come up most in hospital outpatient billing for thyroplasty.

Submitting C1878 on a professional claim

C1878 is a facility code. It belongs on the UB-04 (837I institutional claim), not the CMS-1500 (837P professional claim). A submission on the professional claim form will reject, because Level II C-codes are not recognized under the physician fee schedule. The surgeon bills the CPT procedure code on the professional claim, and the hospital bills C1878 on the institutional claim. Those are two separate submissions for the same encounter.

Our guide to the 837 institutional claim file walks through the UB-04 data elements a device HCPCS code needs before the claim is transmitted.

Missing or mismatched diagnosis codes

C1878 needs a diagnosis code that establishes medical necessity for the synthetic implant. A claim carrying only a symptom code, such as R49.0 dysphonia, is likely to deny. Pair it with the underlying etiology code, such as J38.02 for unilateral vocal cord paralysis. The primary diagnosis should be the condition driving the procedure, with symptom codes reported as secondary. Check payer LCDs for required diagnosis code lists before submission.

Failing to verify pass-through status before billing

Pass-through status is not permanent. A facility that bills C1878 as pass-through after CMS has moved it to packaged status will be overpaid, and CMS will recoup on audit. That makes it one of the more consequential errors in OPPS billing, because recoupment can cover every claim filed across the transition period. Build a quarterly review of the CMS OPPS addenda into the billing compliance calendar.

Denial tracking closes the loop. Track C1878 denials by reason code, and keep pass-through status denials separate from medical necessity denials. It also helps to maintain a payer-specific matrix of which commercial payers recognize the code at all. Retain implant cost records, operative reports, and pass-through verification records under your usual documentation policy, since CMS may request any of them during an audit.

How Pabau keeps device and procedure codes aligned on OPPS claims

Most hospital outpatient billing teams rebuild the C1878 claim by hand for every thyroplasty case. Someone looks up the device code, someone else adds the CPT code and the diagnosis. The pass-through status gets checked against a spreadsheet that may be a quarter out of date.

Practice management software like Pabau replaces that with a saved claim template. The device code, the procedure code, and the supporting diagnosis are stored as one unit. A coder starts from a complete claim rather than a blank form, and missing fields are flagged before submission instead of after a rejection.

The outcome is fewer avoidable denials on a claim type that is expensive to rework. Billing teams also keep the implant cost documentation attached to the encounter, which is what CMS asks for when it audits a pass-through payment.

Simplify outpatient billing workflows

Pabau’s claims management tools help hospital outpatient billing teams pair device codes, procedure codes, and diagnosis codes correctly, reducing OPPS claim errors before submission.

Book a demo

Conclusion

Three conditions decide whether a C1878 claim gets paid. The setting has to be a hospital outpatient department under OPPS. The CPT procedure code has to sit on the professional claim for the same encounter. The diagnosis has to establish medical necessity with the correct laterality.

Pass-through status is what makes this code worth more than an ordinary supply line, and it is also what makes it auditable. Check the status each quarter, keep the implant cost documentation with the encounter, and the claim will hold up under review. Book a demo to see how Pabau handles device and procedure codes on complex outpatient claims.

Continue your research

List Item #1

List Item #2

Frequently asked questions