C8921 HCPCS code: Transthoracic echocardiography with contrast, or without contrast followed by with contrast, for congenital cardiac anomalies; complete

C8921 is the HCPCS Level II code for transthoracic echocardiography with contrast, or without contrast followed by with contrast, for congenital cardiac anomalies; complete. Its Medicare coverage code is D (Special coverage instructions apply): Medicare covers it when its national or local coverage criteria are met. The NCCI unit limit is 1 per day on outpatient hospital claims.

Code details

NCCI unit limits (MUE)

Medicare policy articles for this code

• A56781: Billing and Coding: Transthoracic Echocardiography (TTE) (Wellpoint Federal (MAC - Part A, MAC - Part B))
• A57306: Billing and Coding: Transthoracic Echocardiography (TTE) (CGS Administrators, LLC (MAC - Part A, MAC - Part B))

Covered diagnoses (1,718 ICD-10-CM codes)

The diagnoses most often listed as covered in the policy articles above:

Showing 10 of 1,718. The full list, non-covered diagnoses and CSV export are in Caduvo.

What changed for C8921

• 2008-01-01: C8921 added to HCPCS Level II
• Next scheduled CMS quarterly update (HCPCS and DMEPOS fee schedule): 2027-01-01

Frequently asked questions

What is HCPCS code C8921?

C8921 is the HCPCS Level II code for transthoracic echocardiography with contrast, or without contrast followed by with contrast, for congenital cardiac anomalies; complete. Short descriptor: "Tte w or w/o fol w/cont, com".

Does Medicare cover C8921?

Coverage code D — Special coverage instructions apply. Medicare covers it when its national or local coverage criteria are met.

Which diagnoses support coverage for C8921?

Medicare policy articles that cite C8921 list 1,718 covered ICD-10-CM diagnosis codes across 2 articles. The most cited include A18.84 (Tuberculosis of heart), A36.81 (Diphtheritic cardiomyopathy), A39.53 (Meningococcal pericarditis). A listed diagnosis is necessary but not sufficient; the policy's other criteria still apply.

How many units of C8921 can be billed per day?

1 on outpatient hospital claims; 1 on practitioner claims (NCCI medically unlikely edits).

Related C89 codes

• C8900 — Magnetic resonance angiography with contrast, abdomen
• C8901 — Magnetic resonance angiography without contrast, abdomen
• C8902 — Magnetic resonance angiography without contrast followed by with contrast, abdomen
• C8903 — Magnetic resonance imaging with contrast, breast; unilateral
• C8904 — Magnetic resonance imaging without contrast, breast; unilateral
• C8905 — Magnetic resonance imaging without contrast followed by with contrast, breast; unilateral
• C8906 — Magnetic resonance imaging with contrast, breast; bilateral
• C8907 — Magnetic resonance imaging without contrast, breast; bilateral
• C8908 — Magnetic resonance imaging without contrast followed by with contrast, breast; bilateral
• C8909 — Magnetic resonance angiography with contrast, chest (excluding myocardium)
• C8910 — Magnetic resonance angiography without contrast, chest (excluding myocardium)
• C8911 — Magnetic resonance angiography without contrast followed by with contrast, chest (excluding myocardium)

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Next steps

• Run a reimbursement report for a device billed under C8921
• Watch C8921 for fee, coverage and descriptor changes
• Build a full Medicare revenue model for C8921

Sources: CMS HCPCS Level II release October 2026; CMS DMEPOS fee schedule; CMS NCCI MUE tables; CMS Medicare utilization (physician and DME supplier files); CMS Medicare Coverage Database articles. Fees are Medicare allowables, not commercial rates. Not billing or legal advice.

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