CPT
70450 — CT scan of head/brain without contrast
Same scan can cost 5x more at a hospital than at an imaging center.
Imaging
77066 — Diagnostic mammography, including computer-aided detection when performed; bilateral
A diagnostic mammogram of both breasts, performed when there are clinical indications affecting both breasts or when bilateral evaluation is needed.
- Typical setting: Hospital, imaging center
- National avg charge (illustrative): $150–$350 Medicare allowed; $200–$700 commercial; varies by region
- Most-disputed reason: Billing 77066 (bilateral diagnostic) when only one breast was examined diagnostically — should be 77065 (unilateral)
What it means
What 77066 actually means
A diagnostic mammogram of both breasts, performed when there are clinical indications affecting both breasts or when bilateral evaluation is needed. Like the unilateral version, it involves more views and direct radiologist involvement than a routine screening.
Common errors with this code
What goes wrong on real bills.
Most bills that look correct still contain at least one of these issues. Up to 49% of medical bills contain errors (CFPB).
- Billing 77066 (bilateral diagnostic) when only one breast was examined diagnostically — should be 77065 (unilateral)
- Billing 77066 instead of 77067 (bilateral screening) when the exam was actually a routine screening without specific symptoms
- Billing 77066 and 77067 together on the same date — payers have specific rules about when a screening converts to diagnostic and whether both can be billed simultaneously
If you see 77066 on your bill
Three steps before paying.
1. Get the itemized bill. If your statement only shows a summary, request the CPT-level itemized bill before paying. Generate the request language →
2. Cross-check against the EOB. Compare what your insurer's Explanation of Benefits says you owe versus what the hospital is asking. They disagree more often than people think. Read the bill-vs-EOB guide →
3. Run a free Bill Scan. Upload the bill (and EOB if you have it) and BillBusted will flag the most likely issues with this specific code in your specific state. Run free scan →
Related codes
Other codes in this category.
People who land on 77066 often also see these adjacent codes on the same bill.
CPT
70470 — CT head/brain with and without contrast
If contrast wasn't given, 70470 is the wrong code.
CPT
70486 — CT maxillofacial area; without contrast material
Imaging — verify professional + technical components weren't double-billed.
CPT
70551 — MRI brain without contrast
Same scan can be 5x cheaper at a freestanding imaging center.
CPT
71045 — Chest X-ray, single view
Same image can cost 10x more at a hospital than a freestanding imaging center.
CPT
71046 — Chest X-ray, two views (PA + lateral)
Two-view CXR is standard. Watch the price gap between hospital and freestanding.
Related BillBusted guides
Plain-English reads if you see 77066 on a bill.
77066 FAQ
Plain-English answers.
What does 77066 usually cost?
$150–$350 Medicare allowed; $200–$700 commercial; varies by region. Costs vary by region, payer contract, and whether the service was performed in a hospital outpatient department (which adds a facility fee) versus a free-standing clinic.
What's the most common billing error on 77066?
Billing 77066 (bilateral diagnostic) when only one breast was examined diagnostically — should be 77065 (unilateral)
What should I do if I see 77066 on my bill?
Request the itemized bill and the matching EOB from your insurer. Compare the units/quantity billed against what you actually received. Run a free BillBusted scan to flag the most likely errors specific to 77066 before paying.
Don't pay 77066 blindly.
The free scan tells you in under 60 seconds whether this charge looks reasonable for your situation.