HCPCS code C1824: Cardiac contractility modulation generator

Key takeaways

HCPCS code C1824 describes a generator for cardiac contractility modulation (CCM), an implantable device used to treat symptomatic heart failure with reduced ejection fraction.

Effective October 28, 2025, NCD 20.39 covers CCM nationally under Coverage with Evidence Development, so Medicare pays only for patients enrolled in a CMS-approved clinical research study.

CPT Category III codes 0408T through 0418T report CCM insertion, removal, repositioning, and programming; unlisted CPT codes are no longer the standard.

C1824 and C1898 are packaged into the comprehensive procedure payment, so only K1030 is paid separately through the MAC’s local fee schedule.

Trial claims need a qualifying I50.x diagnosis plus Z00.6, condition code 30, value code D4, modifier Q0, and an 8-digit clinical trial number.

HCPCS code C1824 is a Level II Healthcare Common Procedure Coding System code that describes a generator for cardiac contractility modulation that is implantable. The code is assigned and maintained by the Centers for Medicare and Medicaid Services (CMS) under the HCPCS Level II C-code series. That series covers devices and supplies used in the hospital outpatient setting.

The device reported by C1824 is the implantable cardiac contractility modulation (CCM) generator, most commonly the Impulse Dynamics Optimizer Smart System. CCM therapy delivers non-excitatory electrical signals to the myocardium during the absolute refractory period. Because these signals do not trigger a heartbeat, C1824 is classified separately from pacemaker and ICD generator codes despite the hardware similarity.

C1824 code details at a glance

The table below captures the essential administrative and billing data for HCPCS code C1824. Coders should verify current coverage and payment details against CMS MLN Matters MM14311 and NCD 20.39.

What is cardiac contractility modulation (CCM) therapy?

Cardiac contractility modulation is a device-based therapy for symptomatic heart failure with reduced ejection fraction (HFrEF). Unlike a pacemaker, CCM does not correct rhythm disorders. Instead, the Optimizer Smart System delivers high-energy electrical impulses timed to the absolute refractory period of the cardiac cycle, enhancing the force of each contraction without triggering an additional beat.

The FDA cleared the Optimizer Smart System for patients with New York Heart Association (NYHA) Class III heart failure. Qualifying patients also need an ejection fraction between 25% and 45% and a normal sinus rhythm. The therapy is rechargeable, typically via an external charging vest. Impulse Dynamics, the manufacturer, provides a dedicated coding and reimbursement guide that billing teams should use alongside the national coverage requirements in NCD 20.39.

CCM therapy requires its own HCPCS code because existing pacemaker and ICD generator codes do not accurately describe the device or its clinical function. Using a pacemaker C-code instead of HCPCS code C1824 constitutes an inaccurate representation of the service and will trigger a claim denial or audit flag.

Medicare coverage and eligibility criteria for C1824

Medicare coverage for cardiac contractility modulation is no longer set by local Medicare Administrative Contractor (MAC) policy. Effective October 28, 2025, CMS covers CCM nationally under NCD 20.39, “Cardiac Contractility Modulation (CCM) for Heart Failure,” in the Medicare National Coverage Determination Manual, Chapter 1. This replaced the prior patchwork of MAC-level local coverage determinations with a single national policy.

NCD 20.39 covers CCM under Coverage with Evidence Development (CED). That means Medicare pays for CCM only when the patient is enrolled in a CMS-approved clinical research study. CMS explicitly does not cover CCM for heart failure outside of an approved study. The currently approved study is BRIGHTEN-HF, sponsored by Impulse Dynamics and approved for CED on November 6, 2025.

To qualify for coverage, the patient must meet the FDA market-authorized indication for use. They must also remain symptomatic despite at least three months of optimized guideline-directed medical therapy (GDMT), as determined by the heart team before implantation. Patients are excluded from coverage if they meet any of the following:

• Any contraindication listed in the FDA labeling
• A prior heart transplant
• Age younger than 18 years

Beyond the patient-level criteria, NCD 20.39 requires the CED study itself to meet CMS and AHRQ scientific standards. The study design must include:

• A defined primary outcome (all-cause mortality, heart failure hospitalization, or a composite of the two) followed for at least 24 months
• An active comparator
• A documented care management plan
• A design that supports subgroup analysis by age, ischemic versus non-ischemic cardiomyopathy, CRT status, ejection fraction, and other factors

HIPAA-compliant documentation practices still apply. The patient’s study enrollment and every coverage criterion must be independently verifiable in the medical record before the claim is submitted.

Commercial payer coverage for CCM varies. Some plans follow Medicare’s CED framework; others require separate prior authorization or have not yet issued a coverage policy. Always verify payer-specific requirements before scheduling the implant procedure.

Where is HCPCS code C1824 billed? Setting and place of service

C-codes are typically reserved for hospital outpatient use. CMS bills CCM claims instead under the NCD 20.39 clinical trial framework. MLN Matters MM14311 also sets a broader place-of-service list for professional CCM claims than a standard C-code normally carries. Institutional claims report either type of bill (TOB) 11X with an ICD-10-PCS code, or TOB 12X, 13X, or 85X with a CPT or HCPCS code.

These place-of-service codes apply only to professional claims billed within a CMS-approved CED study, alongside the required trial-billing elements covered later in this article. Billing teams managing implant programs across several sites benefit from multi-location claim tracking to confirm each claim carries the correct POS code and trial documentation before submission.

2026 Medicare HCPCS C1824 fee schedule and reimbursement rates

HCPCS code C1824 no longer has its own separate payment rate. Per CMS MLN Matters MM14311, C1824 and C1898 (the CCM lead code) are not separately payable; CMS packages their payment into the comprehensive CCM procedure. The CPT Category III code reported for the procedure (see the CPT section below) carries the payable line item.

K1030 (external recharging system replacement) is the only CCM-related code still paid on its own. MACs use local fee schedule amounts and DMEPOS gap-fill pricing rules (Medicare Claims Processing Manual, Chapter 23, sections 60.3 and 60.3.1) to pay K1030 claims when applicable.

Use the AAPC HCPCS lookup for an accessible reference view of C1824, or the PGM lookup tool to cross-check current code data against CMS MLN Matters MM14311.

ICD-10-CM diagnosis codes required with C1824

Per CMS MLN Matters MM14311, every CCM claim must carry one specific ICD-10-CM heart failure code as the primary diagnosis. It also needs Z00.6 as the required secondary (“other”) diagnosis identifying the claim as part of a CMS-approved clinical research study. Submitting without both codes is the leading reason CCM claims are returned or denied.

Unlike the pre-October-2025 framework, diastolic and combined heart failure codes are now covered alongside the systolic codes. Coders should still review CMS MLN Matters MM14311 directly, since the covered code list is tied to Medicare Claims Processing Manual updates rather than a MAC-specific policy. For an example of a related diagnosis code write-up, see M15.2.

CPT codes billed alongside HCPCS C1824

HCPCS code C1824 reports the device only. The surgical procedure for implanting the CCM generator is reported with a CPT Category III code created specifically for CCM. Both lines are required; submitting C1824 without the procedural CPT (or vice versa) results in an incomplete claim.

CMS MLN Matters MM14311 lists CPT Category III codes 0408T through 0418T for CCM insertion, replacement, removal, repositioning, and programming. These codes replace the unlisted-procedure approach (CPT 33999 or 93799) that billing teams used before the codes existed.

Institutional claims billed with type of bill 11X instead report one of the ICD-10-PCS codes CMS lists for CCM insertion. Examples include 0JH60AZ or 0JH63AZ for the generator, and 02H63MZ or 02HK3MZ for the leads. Coders should confirm which code set applies to the claim type before submission. Billing teams handling other device-code crosswalks can review C1779 or J0139 for comparable coding patterns.

Clinical trial billing requirements for CCM claims

Medicare covers CCM only under Coverage with Evidence Development. Every claim must carry the coding elements that identify it as part of a CMS-approved clinical research study. These elements sit alongside the diagnosis and procedure codes discussed above, and a MAC will return or deny the claim if any is missing.

MACs return claims submitted with the wrong type of bill, place of service, condition code, modifier, or value code. They deny claims that omit a required ICD-10-CM diagnosis code. MACs are not proactively re-reviewing CCM claims with dates of service between October 28, 2025 and April 6, 2026. They will adjust any claim a practice brings to their attention.

Documentation requirements and billing guidelines for CCM heart failure coding

The documentation burden for HCPCS code C1824 is higher than for most device codes. Medicare requires demonstrated medical necessity against NCD 20.39’s CED criteria, plus proof of enrollment in a CMS-approved clinical study. Missing a single required element is enough to trigger a denial or pre-payment review.

Required documentation elements include:

• Confirmed heart failure diagnosis: Echocardiogram report documenting LVEF between 25% and 45%, with a measurement date generally within 12 months of implantation
• NYHA functional class: Physician assessment documenting Class III status, with clinical basis stated in the record
• Rhythm documentation: ECG or Holter monitor confirming normal sinus rhythm, QRS duration below 130 ms
• Guideline-directed medical therapy (GDMT) history: Medication list and titration history showing optimal medical therapy; failed or intolerable GDMT should be explicitly noted
• CRT assessment: Documentation that CRT was considered, attempted, or deemed inappropriate, with clinical reasoning
• Device identification: Manufacturer, model number, and serial number of the implanted Optimizer Smart System generator
• Operative note: For the implantation procedure, including device labeling, implant site, and lead placement details
• Study enrollment: Confirmation the patient is enrolled in a CMS-approved CED study, such as BRIGHTEN-HF, including the 8-digit clinical trial number
• Pre-authorization: Payer-specific prior authorization number if required (not universally mandated; verify with each payer)

Practice management software like Pabau, through its structured patient record system, can support pre-implant documentation workflows. It centralizes the echocardiogram, NYHA assessments, medication history, and referral documentation in a single patient timeline, reducing the administrative burden at the point of claim submission. Teams using digital clinical forms can also standardize the pre-procedure eligibility checklist to capture each required CED coverage criterion before the procedure date.

Common billing errors and how to avoid them

HCPCS code C1824 has a narrow billing scope, and the most costly errors are entirely preventable. This section covers the denial patterns that recur most frequently in cardiac contractility modulation billing, along with the specific fix for each.

These errors often share the same root cause. Clinical and billing teams work from separate documentation streams, with no shared checklist between them. Teams managing high-volume cardiac implant programs benefit from automated workflow checkpoints that flag incomplete claim prerequisites before submission. Reviewing coding guides for other complex procedure codes, such as CPT code 11044, also reinforces consistent coding practice across a cardiology billing team.

How Pabau supports CCM claims through the CED trial requirement

Billing teams tracking cardiac contractility modulation claims juggle two separate checklists today: The standard diagnosis and procedure codes, and the CED trial-billing elements NCD 20.39 requires. Missing either one delays payment, and the two lists often live in different parts of the record.

Heart failure claims like C1824 rarely stay inside one specialty. A patient’s echocardiogram might sit in a cardiology system, their GDMT history in a general practice or metabolic health practice‘s EMR, and their referral notes somewhere else entirely.

Practice management software like Pabau brings that scattered documentation into one patient record. Billing staff can confirm CED study enrollment, the clinical trial number, and the condition and value codes without leaving the claim screen. That replaces the separate compliance spreadsheet many practices track these details in today.

That consolidation lowers the odds a claim goes out missing one element, the single biggest driver of CCM denials under the new coverage policy.

Streamline cardiac billing with Pabau

Pabau's claims management tools help billing teams track CED trial documentation, attach required diagnosis and modifier combinations automatically, and reduce C1824 denial rates across every approved place of service.

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Conclusion

CCM billing rewards process discipline over code memorization. Getting the codes right matters, but the CED enrollment check is what separates a clean claim from a denied one.

That check has to happen before the implant, not after the claim bounces. Practices running cardiac implant programs should treat CED enrollment verification as a scheduling gate, confirmed alongside prior authorization before the procedure date is set.

Pabau’s claims management software keeps that verification connected to the rest of the patient record, so nothing falls through between scheduling and submission. Book a demo to see how it fits your outpatient program.

Continue your research

Need a billing example for a similarly narrow HCPCS code? HCPCS code J0610 covers the calcium gluconate injection billing and crosswalk rules coders run into with other single-use device and drug codes.

Want to see how diagnosis-code specificity plays out elsewhere? ICD-10 code M16.2 shows how granular code selection works for a different condition with several closely related billable codes.

Want to understand HIPAA documentation requirements for device implants? HIPAA compliance for outpatient practices explains the record-keeping obligations that affect device implant claims.

Frequently asked questions