The same colonoscopy costs $1,500 at a surgery center and $3,800 at a hospital across the street. Same doctor, same equipment, same 30-minute procedure—but the hospital bill is 2.5x higher. Ambulatory surgery centers (ASCs) cost 40–60% less than hospitals for hundreds of common procedures. Here’s a side-by-side comparison so you can decide which is right for you.
1. What is an ambulatory surgery center?
An ambulatory surgery center (ASC) is a facility specifically designed for same-day surgical procedures. You arrive, have your surgery, recover for a few hours, and go home the same day. ASCs don’t have emergency departments, overnight beds (in most cases), or ICUs. This focused design is exactly why they cost less.
There are over 6,100 Medicare-certified ASCs in the U.S., performing more than 28 million procedures per year. About two-thirds are physician-owned, and the rest are owned by hospital systems or corporate chains.
By contrast, a hospital outpatient department (HOPD) performs the same day-surgery procedures but inside a hospital campus. HOPDs charge a separate facility fee on top of the procedure cost—a fee that doesn’t exist at most ASCs. This facility fee alone can add $1,000–$5,000 to your bill. See our facility fees guide for details.
2. Cost comparison: 10 common procedures
Here’s what you’ll typically pay at a hospital vs. a surgery center for the same procedure (charges before insurance):
| Procedure | CPT Code | Hospital (HOPD) | Surgery Center (ASC) | Savings |
|---|---|---|---|---|
| Colonoscopy with biopsy | 45380 | $3,000–$5,500 | $1,200–$2,200 | 45–60% |
| Cataract surgery (one eye) | 66984 | $4,500–$7,000 | $2,000–$3,500 | 50–55% |
| Knee arthroscopy | 29881 | $8,000–$15,000 | $4,000–$7,500 | 45–50% |
| Hernia repair (inguinal, laparoscopic) | 49650 | $7,000–$14,000 | $3,500–$6,500 | 50–55% |
| Carpal tunnel release | 64721 | $4,000–$8,000 | $1,800–$3,500 | 55–60% |
| Rotator cuff repair | 29827 | $12,000–$22,000 | $6,000–$12,000 | 45–50% |
| Tonsillectomy | 42826 | $5,000–$10,000 | $2,500–$5,000 | 50–55% |
| Upper GI endoscopy | 43239 | $3,000–$5,000 | $1,200–$2,500 | 50–60% |
| Spinal injection (epidural steroid) | 62323 | $2,500–$6,000 | $1,000–$2,500 | 55–60% |
| Total knee replacement | 27447 | $35,000–$50,000 | $18,000–$30,000 | 35–45% |
Look up Medicare rates for any procedure:
3. Why ASCs cost so much less
a) No facility fee markup
When you have surgery at a hospital outpatient department, you get two bills: one from the surgeon and one from the hospital (“facility fee”). The facility fee covers the hospital’s overhead—ER, ICU, 24/7 staffing, administration—even though your outpatient procedure used none of those resources. ASCs don’t carry that overhead, so the facility component is dramatically lower.
b) Lower overhead
ASCs are lean operations. No emergency department, no overnight nursing staff, no complex administrative hierarchy. A typical ASC has 2–4 operating rooms and a focused staff. Hospitals have hundreds of departments, each adding layers of cost that get distributed across all patients.
c) Specialization and efficiency
ASCs perform the same procedures hundreds of times per year. This volume creates efficiency: faster turnaround between cases, standardized supply kits, and predictable scheduling. Hospitals deal with emergency cases that disrupt schedules and reduce OR utilization.
d) Better implant pricing
High-volume ASCs negotiate directly with implant and device manufacturers. A knee implant that costs a hospital $8,000 might cost a specialized orthopedic ASC $4,500 due to volume discounts and competitive bidding.
Colonoscopy: $4,200 at a hospital vs. $1,400 at an ASC
A 55-year-old with a PPO plan needed a screening colonoscopy. Her gastroenterologist operated at both the local hospital and an ASC 10 minutes away. At the hospital, the total charge was $4,200 ($1,800 surgeon + $2,400 facility fee). At the ASC, the total was $1,400 ($1,000 surgeon + $400 facility). Same doctor, same sedation, same 25-minute procedure. She saved $2,800 by asking one question: “Do you also operate at a surgery center?”
4. Medicare ASC vs. hospital rates
Medicare publishes separate payment rates for ASCs and HOPDs, making the difference transparent:
| Procedure | CPT | Medicare HOPD Rate | Medicare ASC Rate | ASC as % of HOPD |
|---|---|---|---|---|
| Colonoscopy w/ biopsy | 45380 | ~$850 | ~$510 | 60% |
| Cataract surgery | 66984 | ~$2,100 | ~$1,050 | 50% |
| Knee arthroscopy | 29881 | ~$3,200 | ~$1,900 | 59% |
| Carpal tunnel | 64721 | ~$1,800 | ~$1,000 | 56% |
| Hernia repair | 49650 | ~$3,500 | ~$2,000 | 57% |
For Medicare patients: Your 20% coinsurance is calculated on the Medicare-approved amount. So 20% of a $2,100 HOPD cataract surgery is $420, while 20% of a $1,050 ASC rate is $210. You save on both the rate and your coinsurance.
5. When you should choose a hospital instead
ASCs are not appropriate for every patient or every procedure. Choose a hospital when:
| Factor | Hospital Recommended | ASC May Be Fine |
|---|---|---|
| BMI | Over 40 (morbid obesity) | Under 40 |
| Heart disease | Uncontrolled or recent event | Stable, cleared by cardiologist |
| Sleep apnea | Severe, requiring CPAP | Mild, well-managed |
| Blood thinners | Cannot safely stop medications | Can pause per surgeon’s guidance |
| Procedure complexity | Revision surgery, expected complications | Primary, straightforward procedure |
| Expected stay | Likely overnight or multi-day | Same-day discharge |
| Age | Over 85 with multiple comorbidities | Otherwise healthy at any age |
6. Quality and safety comparison
ASC safety is comparable to hospitals for appropriate procedures:
- Complication rates: Studies in JAMA Surgery show complication rates for ASC-appropriate procedures are similar to hospitals. Some studies show lower infection rates at ASCs.
- Regulation: Medicare-certified ASCs must meet CMS Conditions for Coverage, undergo regular inspections, and report quality data.
- Accreditation: Most ASCs are accredited by AAAHC, Joint Commission, or AAAASF, which require additional quality standards.
- Transfer protocols: All ASCs must have a written transfer agreement with a nearby hospital for emergencies. Unplanned hospital transfers from ASCs occur in less than 0.5% of cases.
- Surgeon volume: ASC surgeons typically perform higher volumes of specific procedures, which is correlated with better outcomes.
7. Insurance coverage at ASCs
Key things to verify before scheduling at an ASC:
- Network status: Confirm the ASC itself is in-network (not just the surgeon)
- Anesthesiologist: Verify the anesthesiologist is also in-network
- Prior authorization: Some procedures require prior auth regardless of facility type
- Cost-sharing: Your copay/coinsurance may be lower at an ASC—check your plan’s benefit summary
- Medicare: Most outpatient procedures are covered at ASCs. Check the CMS ASC covered procedures list
8. How to find an ASC near you
Several ways to find surgery centers in your area:
- BillKarma: Browse our surgery center directory with pricing data for thousands of ASCs
- Ask your surgeon: Most surgeons who operate at ASCs also have hospital privileges—ask where they have OR time
- Medicare.gov: The Care Compare tool lets you search for Medicare-certified ASCs by location
- Your insurance company: Call the number on your card and ask for in-network ASCs near you
Rotator cuff repair: $18,400 saved by choosing an ASC
A 45-year-old with a high-deductible health plan ($6,000 deductible) needed rotator cuff repair. His orthopedic surgeon operated at both the hospital ($24,500 total charge) and an ASC ($8,200 total charge). At the hospital, he’d owe his full $6,000 deductible. At the ASC, the negotiated insurance rate was $6,100, so he owed $6,000 deductible either way—but the ASC’s lower total meant his insurer paid less, and the surgeon confirmed identical equipment and staff at both facilities. For patients with coinsurance (not just deductible), ASC savings flow directly to the patient.
Frequently asked questions
How much cheaper is a surgery center than a hospital?
40–60% cheaper for the same procedure. A colonoscopy that costs $3,000–$5,000 at a hospital costs $1,200–$2,000 at an ASC. The savings come from lower facility fees, lower overhead, and greater efficiency. Medicare data confirms ASC rates are 55–60% of hospital outpatient rates.
Why are surgery centers so much cheaper than hospitals?
No ER, no ICU, no 24/7 staffing overhead. ASCs are purpose-built for outpatient surgery with streamlined operations. They also avoid the hospital “facility fee” markup that can add $1,000–$5,000 to your bill for the same procedure.
Is surgery at an ambulatory surgery center safe?
Yes. Medicare-certified ASCs meet federal safety standards and are regularly inspected. Peer-reviewed studies show complication rates comparable to hospitals for ASC-appropriate procedures, with potentially lower infection rates. Unplanned hospital transfers occur in less than 0.5% of cases.
Does insurance cover procedures at surgery centers?
Yes. Most private insurance and Medicare cover ASC procedures. Your copay or coinsurance is often lower at an ASC because the approved amount is lower. Always verify the ASC and all providers are in your network before scheduling.
What surgeries can be done at an ambulatory surgery center?
Over 5,000 procedure types, including colonoscopy, cataract surgery, knee/shoulder arthroscopy, hernia repair, carpal tunnel, rotator cuff repair, spinal injections, tonsillectomy, and even total joint replacements for healthy patients. The list expands annually as techniques improve.