HCPCS Code C1764: Event recorder, cardiac (implantable)

Key takeaways

HCPCS Code C1764 is the device supply code for an implantable loop recorder, billed by the facility.

C1764 covers the device cost only, and the insertion procedure is billed separately under CPT 33285.

Pass-through payment for C1764 expired on December 31, 2002, so the device cost is packaged into the procedure payment.

Missing medical necessity documentation and filing the code in the wrong setting are the two most common denial triggers.

Practice management software like Pabau keeps the device details, procedure note, and diagnosis codes in one patient record.

HCPCS Code C1764 is the device supply code for an implantable cardiac event recorder. It covers the cost of the device and nothing else. The insertion procedure is billed separately under CPT 33285.

The code is a Level II HCPCS C-code maintained by the Centers for Medicare and Medicaid Services (CMS). It applies only in hospital outpatient departments and ambulatory surgical centers (ASCs).

One detail decides most C1764 claims, and it is easy to miss. The device cost is packaged into the procedure payment rather than paid on its own. Pass-through payment for this code expired on December 31, 2002.

This guide covers the descriptor, the companion CPT codes, and how the code is actually paid in 2026. It also runs through coverage rules, documentation, and the errors that cause denials.

HCPCS Code C1764: definition and official descriptor

HCPCS Code C1764 carries the official descriptor: Event recorder, cardiac (implantable). It is a Level II HCPCS C-code, maintained by CMS, and it represents the supply cost of the implantable cardiac event recorder. The code does not cover the physician’s work or the insertion procedure, which companion CPT codes capture instead.

C-codes exist for OPPS and ASC payment contexts. They are not reported in physician office settings, which use standard CPT and HCPCS Level II codes under the Medicare Physician Fee Schedule. C1764 belongs on the facility’s claim, so putting it on the physician’s CMS-1500 form is a reliable way to earn a denial.

What device does C1764 represent?

C1764 covers the implantable cardiac event recorder, also called an implantable loop recorder (ILR) or insertable cardiac monitor (ICM). It is a small device placed under the skin of the chest wall. It records cardiac electrical activity continuously for two to three years.

The point of that long recording window is capture. A wearable Holter monitor rarely stays on long enough to catch an arrhythmia that happens once a month.

The device is not a pacemaker and it delivers no therapy. Its sole function is recording. Patients return for outpatient interrogation visits, where stored data is downloaded and reviewed. Structured medical forms at every visit support both the implant claim and the later monitoring claims.

Primary clinical indications for the device include:

• Unexplained syncope, or fainting, that persists after a non-invasive workup
• Palpitations with a suspected paroxysmal arrhythmia
• Cryptogenic stroke with suspected atrial fibrillation
• Seizure-like episodes that may have a cardiac origin
• Monitoring for recurrent arrhythmia after ablation or cardioversion

Most of these patients arrive on referral, which matters for billing. The prior workup that a payer will ask for usually sits with the referring practice, inside its general practice software rather than the facility’s records.

Medtronic, Abbott, and Boston Scientific all market insertable cardiac monitors. The device model, serial number, and manufacturer must appear in the claim documentation for C1764.

Where C1764 is billed: settings and claim forms

C1764 is reported by the facility, never by the physician. Two settings apply, and they do not use the same claim format:

• Hospital outpatient department (HOPD): The hospital reports C1764 on the UB-04 alongside the insertion CPT code. Payment follows the Ambulatory Payment Classification (APC) assigned to the procedure, with the device cost packaged into that rate.
• Ambulatory surgical center (ASC): ASCs submit facility claims to Medicare in the professional 837P format, or on paper as the CMS-1500. Revenue codes and the UB-04 do not apply to them.

C1764 is never reported on a physician office visit, an inpatient hospital claim, or a skilled nursing facility claim. Incorrect setting is a denial trigger. Facilities that tie patient scheduling workflows to claim preparation can flag the setting rule at booking, before the claim is ever built.

Companion CPT codes for implantable loop recorders

C1764 represents the device supply. The physician’s insertion procedure and the later monitoring visits are billed separately, using the CPT code set maintained by the American Medical Association. The companion codes for implantable loop recorders are:

The in-person and remote split is where coders slip. CPT 33285 is the primary insertion companion, and the physician reports it on a professional claim while the facility reports C1764 on the facility claim. Both go out for the same date of service.

Related HCPCS codes for cardiac devices

Several other HCPCS C-codes cover cardiac rhythm devices. Knowing which code fits each device prevents unbundling errors and duplicate billing. The table below covers the codes most often confused with C1764:

C1764 is the only code in this group for a purely diagnostic implant. Any cardiac implant that delivers therapy takes a different C-code. Choosing the wrong one triggers National Correct Coding Initiative (NCCI) edits.

How C1764 is paid under OPPS and in ASCs

C1764 carries no separate payment of its own. Under OPPS the device cost is packaged into the Ambulatory Payment Classification assigned to the insertion procedure. Device pass-through for this code expired on December 31, 2002, and it has been packaged ever since.

Rates therefore live with the procedure, not the device. Confirm the current figures in CMS OPPS Addendum B, which lists the payment indicator and APC assignment for every code each year.

Third-party rate databases are estimates. Confirm payment against the current CMS OPPS final rule or your Medicare Administrative Contractor (MAC) fee schedule. The Medicare Physician Fee Schedule lookup tool will not help here, because it prices professional services rather than facility payments.

Medicare and commercial payer coverage

Medicare covers C1764 when it is billed in an eligible facility setting with documented medical necessity. Coverage follows OPPS rules for hospital outpatient departments and the ASC payment system for ambulatory surgical centers.

• Medicare OPPS (HOPD): C1764 is covered when reported on a UB-04 with a valid insertion CPT code and supporting diagnosis codes. Payment arrives through the procedure’s APC rate.
• Medicare ASC: Coverage applies when the procedure sits on the CMS-approved ASC covered surgical procedures list. The device cost is built into the device-intensive procedure rate.
• Local Coverage Determinations (LCDs): Individual MACs may set extra criteria for ILR coverage, usually around syncope workup documentation. Read your MAC’s LCD before filing.
• Commercial payers: Most large payers mirror Medicare’s coverage principles for ILR devices. Medical necessity criteria differ by plan, so confirm the prior authorization requirements before the implant.

C1764 is not covered under Medicare Part B physician office billing. The code is facility-billed only.

Documentation requirements for a C1764 claim

Denials for C1764 usually trace back to incomplete documentation rather than a coding mistake. HIPAA-compliant record keeping across the facility’s files also means the supporting materials survive a payer audit. The required elements are:

• Physician order: A signed order for ILR implantation, with the clinical indication and patient consent
• Operative note: The implant procedure, plus the device model, manufacturer, and serial number
• Device information: Manufacturer, model, and serial number, matching the claim documentation exactly
• Medical necessity statement: Clinical rationale tied to the supporting ICD-10 diagnosis codes
• Prior workup summary: Evidence that less invasive monitoring was tried or was clinically inappropriate
• Facility records: Admit and discharge notes for the outpatient episode, with nursing and anesthesia records where relevant

That prior workup line is the one that catches teams out. Exertional syncope referrals often come from a sports medicine practice that already holds the ambulatory monitoring results. The facility has to request them rather than recreate them.

Practices using digital intake forms can build device fields straight into the procedure workflow. Serial numbers and manufacturer details get captured at the point of care, instead of being reconstructed from memory a week later.

ICD-10 diagnosis codes that support medical necessity

Diagnosis codes are what establish medical necessity for a C1764 claim. The implantable cardiac event recorder suits patients with recurring unexplained symptoms that shorter monitoring has failed to capture. These codes are the ones most often reported alongside C1764:

The diagnosis code has to match the documented indication in the physician’s order and procedure note. Mismatches between the claim and the record are a top audit finding on ILR implant claims. Most MAC LCDs also want proof of prior non-invasive monitoring.

ASC billing rules for implantable devices

ASC billing for implantable devices runs on different rules from HOPD billing. CMS labels a procedure device-intensive when the device makes up a large share of the total procedure cost. For those procedures, the ASC rate is set with the device cost already built in.

• Device offset threshold: CMS uses a device offset percentage to decide which procedures count as device-intensive. Check the current threshold in the annual CMS ASC payment addenda.
• Claim format: ASCs bill Medicare in the 837P professional format. Revenue codes such as 0278 for other implants belong to the hospital’s UB-04, not to an ASC claim.
• Device credit modifiers: Report modifier FB when the device arrives at no cost or with full credit. Report FC when a partial credit applies to a replaced device.
• Packaging: C1764 is packaged, so it is not separately payable in either setting. Hospitals still report it on the OPPS claim, because CMS uses those charges for rate setting.

ASCs that run automated billing workflows can set device-specific flags once, so the right code combination lands on every claim. That saves a coder from reviewing each one by hand.

Common billing errors and how to avoid them

The errors below account for most C1764 denials, and every one of them is avoidable with the right documentation and workflow setup. They are also the same handful that good denial management catches before a claim goes out.

• Filing on the physician’s claim: C1764 is a facility supply code. Putting it on the professional claim for the insertion produces an automatic denial.
• Missing companion CPT code: Submitting C1764 with no valid insertion CPT code on the matching physician claim trips NCCI edits.
• No device serial number in the record: Auditors routinely ask for the manufacturer and serial number. Without them in the procedure note, the claim cannot be validated.
• Incorrect setting: Reporting C1764 in a physician office, inpatient, or skilled nursing context ends in denial. Only HOPD and ASC settings apply.
• Unsupported diagnosis codes: Diagnosis codes that do not appear in the clinical record, or that fail the applicable LCD, produce medical necessity denials.
• Expecting a separate device payment: C1764 has been packaged since 2002. Forecasting a line-item device payment leaves a hole in the revenue projection every quarter.

A pre-claim checklist built specifically for C1764 catches nearly all of this. Cover the setting, the companion CPT code, the device data, and the diagnosis match. Reading the relevant denial codes alongside it turns a rejection into a fix you can apply to the next claim.

How practice management software simplifies cardiac device billing

A single ILR implant generates a facility claim, a companion physician claim, device documentation, and a diagnosis code that has to match the record. Cardiology facilities and ASCs handling that volume on paper see higher denial rates for exactly that reason. Understanding how practice management software works across multi-code billing is the first step to fixing it.

Practice management software like Pabau gives your team one patient record that holds the procedure note, the device details, and the diagnosis codes together. Nothing has to be chased from a paper log after the fact. Capture the device information through EHR integration workflows and it is already sitting there when the claim is built.

From there, Pabau’s claims management software submits electronically through our Claim.MD integration, then tracks each claim’s status back into the same record. Then a payer asks you to validate a C1764 claim. The order, the operative note, the device data, and the diagnosis codes are all attached to one encounter.

That is the difference between a two-day audit response and a two-week one. Nothing has to be pulled from three separate systems and reconciled by hand.

Keep device claims and their records together

Pabau holds the operative note, device serial number, and diagnosis codes in one patient record, then submits the claim through our Claim.MD integration. Your team stops rebuilding documentation after the fact.

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Conclusion

Treat C1764 as a reporting obligation rather than a revenue line and most of the confusion around it disappears. The code has been packaged for over two decades, so it earns nothing on its own. It still has to be on the claim, coded correctly, with the device data behind it.

The trade-off worth remembering is where the effort pays off. Chasing the fee schedule every January gains you very little on this code. Getting the serial number, the order, and the diagnosis into the record on the day of the implant is what keeps the money.

If your team is still reconstructing device documentation after the claim goes out, that is the workflow to change first. Book a demo to see how Pabau keeps implant documentation and claim submission in one place for cardiology and ASC teams.

Continue your research

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Billing another OPPS device supply code? C1813 walks through the same facility-claim mechanics for a different implant category.

Working through a spine device claim? C1821 covers the device-intensive designation and how it shapes the ASC rate.

Stuck waiting on payer approvals? Prior authorization software explains how practices cut the delay before an implant procedure is scheduled.

Frequently asked questions