Verimedix runs ambulatory surgery center billing services for single- and multi-specialty ASCs - facility-side UB-04 claims, payment-indicator and covered-procedures-list accuracy, implant and device invoice capture, multiple-procedure discounting, and denial recovery on the high-dollar cases generalist billers get wrong. Typical engagements run 4-7% of net collections with no setup fee and no long-term lock-in.
Ambulatory surgery center billing services are outsourced facility-side revenue cycle management for an ASC - the UB-04 facility claim for use of the room, nursing and packaged supplies, not the surgeon's separate professional claim. ASC billing services cover payment-indicator and covered-procedures-list verification, prior authorization, implant and device invoice documentation, packaging rules, multiple-procedure and bilateral discounting, claim submission, denial appeals and A/R follow-up. Pricing typically runs 4-7% of net collections, or a flat fee per surgical case.
Ambulatory Surgery Centers bill as facilities under Medicare's ASC payment system, which is based on the Outpatient Prospective Payment System (OPPS) but uses ASC-specific payment rates that are approximately 50–60% of the Hospital Outpatient Department (HOPD) rates for most procedures. The ASC must be a Medicare-certified facility and is reimbursed for the facility fee—which includes nursing, supplies, equipment use, and most ancillary services—while the operating surgeon, anesthesiologist, and other physicians bill separately under Part B for their professional services. Understanding what is packaged (bundled) into the ASC payment versus what is separately payable is the foundational challenge of ASC facility billing.
Each CPT/HCPCS procedure assigned to the ASC setting carries an ASC Payment Indicator that determines how it is reimbursed. Indicator 'A1' means the procedure is paid at the ASC rate; 'N1' indicates it is packaged into the payment for a primary procedure (not separately payable); 'R2' means it is not paid in the ASC setting; 'K2' means it is a covered ancillary service paid separately only in the ASC context. Device-intensive procedures (those where the device cost is a significant portion of total cost) may qualify for device pass-through under HCPCS C-codes or specific device APC categories. New technology APCs (NTAPs) may also apply for qualifying technologies. CMS updates the ASC payment system annually in the OPPS/ASC final rule published each November, effective January 1.
Commercial payer contracting for ASCs is an additional layer of complexity. Unlike Medicare's fixed fee schedule, commercial payers negotiate rates that may be percentage of billed charges, case rates, or percentage of Medicare. The ASC's chargemaster must be maintained at appropriately high charge levels to ensure percentage-of-charges contracts yield adequate reimbursement. Managed care contract review, with specific attention to carve-outs for implants, high-cost drugs, and unlisted procedures, is essential. Modifier SG (ASC facility service) has been deprecated from Medicare claims but remains in use by some commercial payers; verify each payer's specific requirements for ASC facility claim submission format (UB-04 vs. 1500).
Two CY 2026 changes reset the ASC revenue picture. CMS finalized a 2.6% update to ASC payment rates and, in the same rule, began phasing out the inpatient-only list over three years, with the musculoskeletal codes going first and full elimination scheduled for January 1, 2028. CMS also relaxed the general exclusion criteria for the ASC covered procedures list, so procedures that were previously off the table - including cardiac ablation, lumbar fusion and vascular embolization codes - are now ASC-eligible. The practical effect is that ASC case mix is getting heavier and more device-intensive at exactly the moment payers are tightening implant documentation. A procedure counts as device-intensive when the device cost is at least 30% of the ASC procedure rate, and those are the claims where a missing invoice line costs the most.
Published ranges for outsourced billing run 4-10% of net collections across all specialties. Ambulatory surgery centers are usually quoted 3-9%, and where a center lands inside that band has little to do with claim count. An ASC files far fewer claims than a busy physician office, but each one is a project: multiple procedures on a single facility claim, discounting rules, implant invoices, payer-specific packaging matrices, and a facility-coding skill set that is genuinely scarce.
The fee only makes sense measured against the cost of doing it in-house and the cost of getting it wrong. A certified facility coder plus an A/R follow-up specialist is a six-figure payroll line before benefits, software and coverage for vacations. Meanwhile a single high-dollar case can go unpaid on a technicality - a missing implant invoice, a procedure billed that was not on the payer's covered list, or a packaged supply billed separately and later recouped. Industry-wide, roughly 15-20% of ASC facility claims are denied on first submission, and on an implant-heavy orthopedic or spine case one denial can erase the margin on the entire case.
Verimedix quotes ambulatory surgery center billing at 4-7% of net collections depending on case volume, specialty mix and how implant-intensive the case mix is. High-volume centers with stable payer contracts can take a flat per-case fee instead, and centers that only need certified ASC facility coders can buy coding on its own. There is no setup fee and no multi-year contract.
| Fee model | Typical range | Best fit |
|---|---|---|
| Percentage of net collections | 4-7% of net collections | Most single- and multi-specialty ASCs; the vendor is paid only when the center is |
| Flat fee per case | Negotiated per surgical case | High-volume centers with predictable case mix and stable contracted rates |
| Facility coding only | Priced per case | Centers that keep A/R in-house but need certified ASC facility coders |
| Implant-heavy / out-of-network | Upper band, negotiated | Orthopedic, spine and cardiac centers where device documentation and appeals drive the work |
Figures are engagement ranges, not a rate card. Prior authorization volume, out-of-network mix and the size of an existing A/R backlog all move the number, so we quote after a look at your case log and aging.
Below are commonly billed codes our certified coders manage for ambulatory surgery center practices. Always confirm payer-specific coverage and current code values.
| Code | Description | Billing note |
|---|---|---|
27447 | Total knee arthroplasty (TKA) | ASC-eligible per CMS since 2020; device-intensive; verify ASC payment indicator and implant pass-through eligibility; document device cost on claim |
66984 | Extracapsular cataract removal with insertion of intraocular lens prosthesis | Among the highest-volume ASC procedures; packaged supply costs; IOL reported as device on claim |
45378 | Colonoscopy, flexible, with or without single or multiple biopsy(ies) | APC packaged; higher-complexity GI procedures (polypectomy 45380, 45385) have higher ASC payment rates |
43239 | Upper GI endoscopy (EGD) with biopsy | Common ASC GI procedure; confirm payer coverage in outpatient setting; document medical necessity |
29881 | Arthroscopy, knee, surgical; with meniscectomy | High-volume orthopedic ASC procedure; 90-day global for professional claim; ASC facility bills separately |
52000 | Cystourethroscopy (diagnostic) | Common urology ASC procedure; verify payment indicator—may be packaged when performed with therapeutic procedure |
62321 | Injection, epidural, lumbar or sacral (including imaging guidance if performed) | High-volume pain management ASC procedure; confirm imaging component bundled with 2017 CPT changes |
C1769 | Guide wire (HCPCS device code) | Example device pass-through code; report on facility claim when device qualifies for separate ASC payment |
Our standard operating procedures for ambulatory surgery center revenue cycle management — the step-by-step workflow we follow on every claim:
These are the issues we see most often in ambulatory surgery center billing — and exactly how we resolve them:
Under ASC payment rules, most drugs, supplies, and diagnostic tests are packaged into the APC/procedure payment and not separately payable. Billing them separately results in denial or recoupment. Fix: maintain an up-to-date packaging matrix in your CDM; configure your billing system to suppress packaged items from separate billing while retaining them for chargemaster reporting.
ASC facility claims for Medicare must be submitted on UB-04. Some commercial payers accept or require CMS-1500 for ASC claims. Submitting on the wrong form results in rejection. Fix: create a payer-specific submission format matrix and configure your clearinghouse routing to match.
Device pass-through claims (C-codes) are denied when the claim lacks the device invoice, HCPCS code match to the implant used, and documentation of device use in the operative report. Fix: implement an implant log capture process at the time of surgery; route device receipts to the billing department same-day.
CMS publishes an annual list of procedures covered in the ASC setting. Performing a procedure not on the ASC-covered list for Medicare results in non-payment. Fix: maintain the current year's ASC covered procedure list in your scheduling workflow; flag any procedure not on the list for payer-specific coverage verification before scheduling.
ASCs on percentage-of-billed-charges contracts lose revenue when their chargemaster has low charge levels. Fix: benchmark charges against regional peers and update the CDM annually to ensure charges are set at levels that support adequate reimbursement under percentage-of-charges contracts.
Verimedix works inside the systems ambulatory surgery center practices already use, including:
Outsourced ambulatory surgery center billing is usually quoted at 3-9% of net collections, and Verimedix engagements typically land at 4-7% depending on case volume, specialty mix and implant intensity. High-volume centers can take a flat per-case fee instead, and coding-only engagements are priced separately. There is no setup fee and no long-term contract.
CMS finalized a 2.6% update to ASC payment rates for CY 2026 and started a three-year phase-out of the inpatient-only list, beginning with musculoskeletal procedures and ending January 1, 2028. It also relaxed the exclusion criteria for the ASC covered procedures list, adding procedures such as cardiac ablation, lumbar fusion and vascular embolization. Centers should re-verify payment indicators and payer coverage for any newly eligible case before scheduling it.
The ASC submits a facility claim (UB-04) for the use of the facility, nursing, and packaged supplies/equipment. The physician (surgeon, anesthesiologist, assistant) submits a separate professional claim (CMS-1500) for their personal services. These are independent revenue streams billed to the same payer but processed separately.
No. Medicare no longer requires modifier SG on facility claims submitted on the UB-04. However, some commercial payers still require SG to identify ASC facility services—always check payer-specific billing guidelines.
For procedures where the device cost is substantial (e.g., joint replacement implants), the ASC reports the device using a HCPCS C-code on the facility claim. If the device qualifies for device pass-through payment under Medicare, it is reimbursed separately in addition to the APC payment for the procedure. Device offset rules may reduce the APC payment when a device offset applies.
No. The ASC facility fee does not include anesthesiologist or CRNA professional services. The anesthesia provider bills separately. The ASC may include the cost of anesthesia supplies and drugs in the facility claim as packaged items under the surgical APC.
Report the procedure with modifier -74 (discontinued outpatient procedure after anesthesia induction). Medicare pays a reduced ASC facility rate for cases discontinued after anesthesia was administered. Modifier -73 is used if the case was cancelled before anesthesia.
For bilateral procedures on the same day, the ASC bills the procedure twice with RT and LT modifiers (or modifier -50 for bilateral, per payer guidance). Medicare pays 150% of the single procedure rate for bilateral procedures (100% for the first side, 50% for the second side) when each side is documented as a separately performed procedure.
CMS updates the ASC covered procedure list annually as part of the OPPS/ASC final rule, typically published in November and effective January 1 of the following year. Verimedix recommends reviewing the final rule each November to update your scheduling eligibility matrix and chargemaster.
Verimedix handles the entire ambulatory surgery center revenue cycle — coding, submission, denials, and A/R — so your team can focus on patients.