A coronary artery bypass graft (CABG) is one of the most expensive surgeries performed in the United States. In 2026, the total billed cost ranges from $70,000 to over $200,000 depending on hospital, geography, payer type, and the number of grafts needed. The average sits around $120,000. Without insurance, you face chargemaster prices that can hit $200,000 or more. With Medicare, your out-of-pocket exposure is much lower. With Medicaid, many patients pay nothing at all.
Quick Answer: CABG surgery costs $70,000 to $200,000 in 2026, with a national average around $120,000. Medicare patients typically pay 20% of covered costs after the $1,736 Part A deductible. Uninsured patients should request charity care immediately. Nonprofit hospitals are legally required to offer it. Upload your bill to the CoveredUSA Bill Analyzer to check every line item against what Medicare actually pays.
This guide breaks down the billing codes, insurance payment rates, and every legitimate way to reduce what you owe.
What CPT 33533 Actually Covers
CPT code 33533 is the primary procedure code for a coronary artery bypass using a single arterial graft. In plain terms: the surgeon takes an artery (most commonly the internal mammary artery) and routes it around a blocked coronary artery to restore blood flow to the heart.
The full CPT family for arterial bypass grafts:
| CPT Code | Description | 2026 Medicare Physician Rate |
|---|
| 33533 | Single arterial graft | $1,757.89 |
| 33534 | Two arterial grafts | $2,115.22 |
| 33535 | Three arterial grafts | $2,264.56 |
| 33536 | Four or more arterial grafts | $2,485.00 |
Note: these are the surgeon's professional fee reimbursements from Medicare. The facility (hospital) payment is billed separately and is dramatically higher. A single surgery bill includes the surgeon fee, facility fee, anesthesia, perfusionist, and post-op monitoring, all coded and billed separately.
For venous grafts, add-on codes like 33517 through 33523 layer on top of 33533. A triple bypass using one arterial graft plus two venous grafts would use 33533 as the base code plus add-ons.
DRG 233: The Hospital's Side of the Bill
While CPT codes track the physician's work, DRGs (Diagnosis Related Groups) determine what Medicare pays the hospital for the entire inpatient stay. CABG procedures map to several DRGs depending on whether cardiac catheterization was performed and the patient's severity level.
2026 Medicare DRG payment rates for CABG:
| DRG Code | Description | 2026 Medicare Payment | Avg. Length of Stay |
|---|
| 231 | CABG with PTCA with MCC | $85,200 (est.) | 14.2 days |
| 232 | CABG with PTCA without MCC | $58,400 (est.) | 10.1 days |
| 233 | CABG with cardiac cath or ablation, with MCC | $55,632 | 12.3 days |
| 234 | CABG with cardiac cath or ablation, without MCC | $39,751 | 8.7 days |
| 235 | CABG without cardiac cath, with MCC | $48,100 (est.) | 11.4 days |
| 236 | CABG without cardiac cath, without MCC | $30,481 | 7.6 days |
MCC = Major Complication or Comorbidity. If you have diabetes, kidney disease, heart failure, or another serious condition on top of your coronary artery disease, your case may code to a higher DRG with a larger Medicare payment.
These payments represent what Medicare pays the hospital, not the full chargemaster price. The actual billed charge from the hospital is typically 3 to 5 times these amounts. The chargemaster price is what uninsured patients see on their bill initially, before any negotiation.
Total Cost by Payer: What You Actually Pay in 2026
Your real out-of-pocket cost depends almost entirely on your insurance situation.
If You Have Medicare (Parts A and B)
Medicare covers CABG as medically necessary under Part A (hospital) and Part B (physician services). Your cost breakdown for 2026:
- Part A hospital deductible: $1,736 per benefit period (you pay this once)
- Days 1 to 60 in hospital: $0 coinsurance after the deductible
- Days 61 to 90: $434/day coinsurance
- Physician fees: Covered under Part B, 20% coinsurance after the $283 annual deductible
- Anesthesia: Covered under Part B at 20%
For a typical 7 to 10 day CABG stay, most Medicare patients pay between $2,500 and $6,000 total out of pocket assuming no complications push the stay past 60 days. Medicare Supplement (Medigap) plans cover most or all of this coinsurance.
Medicare Advantage plans follow different cost-sharing rules. Check your specific plan's Summary of Benefits for CABG coverage details, prior authorization requirements, and hospital network restrictions before scheduling surgery.
Starting January 1, 2026, the CMS Transforming Episode Accountability Model (TEAM) launched a mandatory bundled payment program for CABG at 741 hospitals across 188 metropolitan areas. Under TEAM, these hospitals are accountable for all Medicare spending on your bypass surgery plus 30 days of follow-up care. This may affect which hospitals and surgeons participate in your local network. Confirm coverage before your procedure.
Source: CMS.gov TEAM Model overview
If You Have Medicaid
Medicaid covers CABG in all states as a medically necessary procedure. In most states, Medicaid pays 100% of the allowed amount with no deductible and no coinsurance. Some state Medicaid programs charge a small copay, but federal law caps Medicaid copays and cost-sharing at nominal amounts.
The catch: Medicaid reimbursement rates are lower than Medicare rates. Not every cardiac surgery center accepts Medicaid. Call ahead to confirm the hospital and surgeon are in-network for your state's Medicaid program.
If You Have Private Insurance (Employer or ACA Marketplace Plan)
Private insurance typically negotiates rates somewhere between Medicare and the full chargemaster price. Your actual out-of-pocket depends on:
- Your deductible (ACA plans range from $500 to $8,700 for individuals in 2026)
- Your out-of-pocket maximum (capped at $10,600 for individual ACA plans in 2026)
- Whether the hospital and surgeon are in-network
- Whether your plan required prior authorization (if skipped, you may owe more)
For most privately insured patients, out-of-pocket costs max out at the plan's out-of-pocket limit, typically $5,000 to $10,600.
If You Are Uninsured
Without insurance, hospitals bill at chargemaster rates, which are dramatically inflated. For CABG, you could receive an initial bill of $150,000 to $250,000. However, this is almost never what you actually have to pay.
Two immediate actions for uninsured patients:
- Apply for charity care through the hospital's financial assistance program (see section below)
- Upload your itemized bill to the CoveredUSA Bill Analyzer to identify overcharges and errors before paying anything
Charity Care: What Nonprofit Hospitals Must Offer You
All nonprofit hospitals, roughly 60% of US hospitals, are required by the Affordable Care Act and IRS rules to maintain a written Financial Assistance Policy (FAP). This is often called charity care.
Income thresholds at most nonprofit hospitals (2026):
| Household Size | 200% FPL (2026) | 400% FPL (2026) | Typical Benefit |
|---|
| 1 | $31,920 | $63,840 | Full write-off below 200%; 50-80% discount to 400% |
| 2 | $43,280 | $86,560 | Same |
| 3 | $54,640 | $109,280 | Same |
| 4 | $66,000 | $132,000 | Same |
| 5 | $77,360 | $154,720 | Same |
| 6 | $88,720 | $177,440 | Same |
| 7 | $100,080 | $200,160 | Same |
| 8 | $111,440 | $222,880 | Same |
Source: ASPE.HHS.gov 2026 Federal Poverty Guidelines
Some hospitals extend partial discounts up to 600% FPL. A family of four earning $132,000 might still qualify for a 30 to 50% reduction at certain systems.
Under IRS rules, nonprofit hospitals must give you 240 days from the first billing notice to apply for financial assistance. Do not pay anything or make payment arrangements before you apply. Paying in full can waive your eligibility at some institutions.
How to apply for hospital charity care:
- Ask for the itemized bill on the same day you ask for the charity care application
- Request the hospital's written Financial Assistance Policy (they must provide it)
- Gather income documentation: most recent tax return, two recent pay stubs, or a letter from your employer
- Submit the application with all documentation
- Get written confirmation of the approved discount before making any payment
- If denied, appeal in writing citing your income and household size against their published FPL thresholds
How to Dispute Errors on a CABG Bill
CABG surgeries generate complex, multi-page bills with dozens of line items. Billing errors are common. Reported error rates for hospital bills run between 30% and 80% depending on the study.
Common errors on CABG and cardiac surgery bills:
- Duplicate charges: Same supply or service billed twice
- Upcoded DRGs: A DRG 236 (without MCC) billed as DRG 233 (with MCC) adds $25,000+ to the facility payment
- Unbundling: Procedure components billed separately when they should be included in the primary code
- Phantom charges: Items like operating room supplies listed but never documented in the medical record
- Wrong CPT codes: A single-vessel bypass (33533) billed as a multi-vessel code
The CoveredUSA Bill Analyzer compares each line on your hospital bill against Medicare's published payment rates and flags charges that are significantly above the Medicare benchmark. For a $120,000 CABG bill, even a 10% error rate represents $12,000 in potentially disputable charges.
How to Negotiate What You Owe
Even after insurance pays its share, you may have thousands of dollars left on the bill. Before you pay:
- Request the itemized bill. Not the summary statement. The full itemized bill with CPT codes and charge descriptions. You have a right to this document.
- Compare to your Explanation of Benefits (EOB). The EOB from your insurer shows what was billed and what was paid. Discrepancies are common.
- Ask for the cash-pay rate. Hospitals often offer uninsured or underinsured patients a "cash discount" of 30 to 50% off the remaining balance if you pay in a lump sum.
- Negotiate a settlement. Hospitals routinely accept 40 to 70 cents on the dollar for accounts that might otherwise go to collections. Call the billing department and ask to speak with a patient advocate.
- Request a payment plan. Most hospitals will set up interest-free payment plans. Federal law under the No Surprises Act and ACA provisions limits aggressive collection for patients who apply for financial assistance.
- Check for state programs. Some states have hospital charity care programs or patient protection funds that supplement what the hospital itself offers.
What Drives CABG Cost Variation
Not every $120,000 estimate applies to your situation. These factors push costs higher or lower:
- Number of grafts: Single-vessel (one blocked artery) is cheaper than quadruple bypass (four blocked arteries). Each additional graft adds surgical time, supplies, and potentially a higher DRG.
- Off-pump vs. on-pump: Off-pump CABG (beating heart surgery, no heart-lung bypass machine) is technically demanding but can reduce complications and hospital length of stay, cutting costs modestly.
- Hospital type and geography: Academic medical centers in major metro areas bill higher than community hospitals in rural areas. New York and California hospitals skew significantly above the national average.
- Complications: A patient who develops post-op infection, prolonged ventilation, or renal failure codes to a higher-severity DRG, extending the stay and the bill.
- Concurrent procedures: If cardiac catheterization or ablation is performed at the same admission, the case maps to DRG 233 or 234 rather than the lower-paying DRG 235/236, meaning the hospital gets paid more.
How to Apply for Coverage Before Surgery (If Uninsured)
A CABG is rarely an emergency scheduled with weeks of advance notice. If you have time before your procedure, apply for coverage now. Even if surgery is imminent, emergency Medicaid and marketplace special enrollment periods may apply.
Enrollment windows and steps:
- Check Medicaid eligibility immediately. Medicaid has no enrollment window. You can apply any time of year. If you qualify, it can cover surgery scheduled within days or weeks. Visit Medicaid.gov or your state's Medicaid portal to apply.
- Screen your eligibility at CoveredUSA. Use the free screener at coveredusa.org/screener to get a fast read on whether you qualify for Medicaid, a marketplace plan, or Medicare.
- Qualifying life event for ACA marketplace. Loss of other coverage, change in household size, and certain other events trigger a 60-day Special Enrollment Period on healthcare.gov. Apply at HealthCare.gov.
- Documents needed for Medicaid:
- Proof of identity (driver's license or passport)
- Proof of state residency
- Social Security number
- Proof of income (tax return, pay stubs, or employer letter)
- Proof of citizenship or immigration status
- Common reasons applications get denied:
- Income above the state's Medicaid threshold (check your state's limit)
- Missing documentation
- Not enrolled as state resident
- Prior Medicaid fraud or debt in another state
If you already have Medicare or a marketplace plan and believe coverage is being wrongfully denied for your CABG, contact your state's Health Insurance Assistance Program (SHIP) at shiphelp.org for free counseling.
Frequently Asked Questions
What does CPT 33533 mean on my bill?
CPT 33533 is the procedure code for a single coronary artery bypass using an arterial graft. If you see it on your bill, the surgeon performed a single-vessel arterial bypass, the most common type using the internal mammary artery. The 2026 Medicare physician payment for this code is $1,757.89. If your bill shows a much higher amount for 33533, that represents the hospital's chargemaster rate, which is negotiable.
What is DRG 233 and how does it affect my bill?
DRG 233 is the hospital classification code for a coronary bypass with cardiac catheterization or open ablation performed at the same admission, in a patient with a Major Complication or Comorbidity (MCC). Medicare pays hospitals $55,632 for a DRG 233 case in 2026. Your actual bill from the hospital will be higher than this. The DRG payment is the cap of what Medicare will pay, not the total charged amount.
How much does CABG cost without insurance in 2026?
The chargemaster (list) price ranges from $100,000 to $250,000 at most US hospitals. However, uninsured patients at nonprofit hospitals are entitled to charity care, which can reduce or eliminate the bill entirely for low- and moderate-income patients. The average self-pay rate (after charity care or cash discounts) is roughly $30,000 to $80,000, though individual outcomes vary widely.
Does Medicare cover open-heart surgery?
Yes. Medicare Part A covers the hospital stay for CABG as medically necessary. Part B covers physician fees. In 2026, your primary cost is the $1,736 Part A deductible plus 20% of Part B physician charges. Most patients are also enrolled in Medicare Advantage or a Medigap supplement that covers most of this coinsurance.
What is the TEAM model and does it affect my CABG in 2026?
The CMS Transforming Episode Accountability Model (TEAM) launched January 1, 2026. It applies to 741 specific hospitals in 188 metropolitan areas. Under TEAM, these hospitals receive a bundled payment covering the surgery plus 30 days of post-discharge care. From a patient perspective, your cost-sharing does not change under TEAM. The model affects how the hospital is paid, not your deductible or coinsurance. However, TEAM may influence which post-acute facilities your hospital recommends, since the hospital now shares financial risk for your recovery.
How do I find billing errors on my CABG bill?
Request a complete itemized bill with CPT codes. Then compare each CPT code and charge against the Medicare published rate for that code. Charges more than 3 to 5 times the Medicare rate are candidates for negotiation. You can upload your itemized bill to the CoveredUSA Bill Analyzer at coveredusa.org/medical-bill-analyzer, which runs an automated comparison against Medicare benchmark rates and flags outliers.
Can I apply for Medicaid to cover a CABG that already happened?
In most states, Medicaid can cover medical expenses retroactively for up to 3 months before the application date if you were eligible during that period. This is called "retroactive Medicaid." Apply as soon as possible after the procedure if you were uninsured at the time. Check with your state's Medicaid office or visit Medicaid.gov for state-specific rules.
What is charity care and how do I apply for it?
Charity care is a financial assistance program that all nonprofit hospitals are required to maintain under ACA and IRS rules. Eligibility is based on income relative to the Federal Poverty Level. Patients below 200% FPL typically qualify for full write-offs; patients between 200% and 400% FPL qualify for partial discounts. To apply, ask the hospital billing department for the Financial Assistance Policy and application form. You have up to 240 days from the first billing notice to apply.
Sources: Medicare.gov surgery coverage, CMS.gov TEAM model, ASPE.HHS.gov poverty guidelines, CMS ICD-10 MS-DRG Definitions Manual, STS.org CABG payment model update
