ASC billing services for the facility claim and payment indicators

The codes and indicators we work most

Modifiers that matter

Payer rules to know

Top denials in asc billing services for the facility claim and payment indicators

What does ASC billing cover?

ASC billing is the facility side of outpatient surgery done in an ASC, a distinct entity that exists to provide surgery for patients who do not need hospitalization. Under 42 CFR 416.2 the expected stay does not exceed 24 hours, and the center must hold an agreement with CMS. The ASC bills for the room, nursing, supplies and most implants. The surgeon and anesthesia professional bill separately.

Colonoscopy rules are on gastroenterology billing and implant rules on orthopedic billing. This page covers the ASC facility claim itself.

Which claim form does an ASC use?

For Medicare, an ASC bills its MAC on the ASC X12 837P professional claim or, in rare cases, on the CMS-1500. Chapter 14, section 10.1 of the Medicare Claims Processing Manual says this in plain terms. Hospitals use the institutional UB-04 instead.

The place of service code is 24 for a procedure performed in an ASC (Chapter 14, section 50). The same section says ASCs have not been required to put the SG modifier on Medicare facility claims since January 1, 2008.

A hospital that runs its own surgery center has a choice. Section 10.1 says a hospital-operated facility can be treated either as an ASC or as a provider-based department of the hospital. Which one you chose decides the form and the fee schedule.

Commercial plans publish their own ASC rules in provider manuals, and some differ from Medicare on form and modifiers. We read each payer's manual before the first claim and do not assume Medicare's rules carry over. Our hospital and facility billing team prepares both claim types.

How do the ASC covered procedures list and payment indicators work?

Medicare pays an ASC only for procedures on the ASC covered procedures list, and the payment indicator on each line says how it is paid. CMS publishes both in the ASC addenda each quarter. The CMS addenda page shows an October 2026 file updated October 13, 2026.

The list is wider in 2026. Under 42 CFR 416.166(b)(2), for services on or after January 1, 2026, a covered procedure must be separately paid under the hospital outpatient system and must not be on the inpatient-only list, be reportable only with an unlisted CPT code, or be excluded under 42 CFR 411.15. The CY 2026 final rule (90 FR 53448) moved five older exclusion criteria into nonbinding physician considerations, added 276 procedures for that reason, and added 271 codes removed from the inpatient-only list.

Transmittal 13983 (October 8, 2026) added ten Category III CPT codes, and 1091T, 1092T and 1093T carry J8.

How do ASC payment rates differ from hospital rates?

ASC rates start from hospital outpatient weights but follow their own rules. Chapter 14, section 40 sets most rates as a percentage of OPPS rates. Each procedure maps to an APC weight, and the ASC rate is that weight times the ASC conversion factor (42 CFR 416.167 and 416.171).

Screening colonoscopy cost sharing is the exception. Chapter 14, section 30 says coinsurance for screening colonoscopy and screening flexible sigmoidoscopy is being reduced in steps until it is waived for dates of service on or after January 1, 2030. Coding is on our gastroenterology page.

How do we bill multiple procedures in an ASC?

When an ASC performs more than one covered procedure in the same operative session, Medicare pays 100 percent of the highest-paying procedure and 50 percent of each other procedure that is subject to the discount. Chapter 14, section 40.5 says this applies even when the procedures share a code. 42 CFR 416.172(e) sets the same 50 percent rule.

Which codes are discounted is not a guess. Addendum AA carries a column marking each surgical procedure that is subject to multiple procedure discounting, with a Y. The reduction is the last pricing step, and ranking uses the lower of the billed charge or the ASC payment amount.

Bilateral work follows the same rule. Section 40.5 says a bilateral procedure is reported as two procedures, on two lines or one line with 2 units, and the 50 percent reduction applies. Section 20.3 adds that if a code is part of a more comprehensive code billed the same day, only the comprehensive code is covered, under the NCCI rebundling rules.

Which modifiers do ASCs use?

A short list of modifiers changes ASC payment, and each has a rule in Chapter 14.

Section 40.4 says a claim is denied when the procedure is stopped before the patient is taken into the operating or treatment room. A terminated claim needs an operative report on file giving the reason, services and supplies provided, time in each stage, and the planned code.

Do not send FB and FC on the same code line. Section 40.8 prohibits it, and the FB or FC price is set before the multiple procedure reduction.

How do ASCs bill implants and device-intensive procedures?

An ASC does not bill most implants separately. Chapter 14, section 40 says implant payment is part of the procedure payment, except for OPPS pass-through devices. Packaged items get no separate line; fold their charges into the separately payable procedure.

A device-intensive procedure involves an implantable device that must be surgically inserted and has a code-level device offset above 30 percent (42 CFR 416.171(b)(2)). The CY 2026 final rule gives new codes with no claims data a 31 percent default offset. The device part of the rate is held to the hospital figure.

The implant log should show any manufacturer credit and its date, because that decides FB or FC. See orthopedic billing for joint implants.

How are separately payable drugs and biologicals billed in an ASC?

An ASC is paid separately for a drug or biological only when the hospital outpatient system pays for it separately and it is given integral to the surgery. 42 CFR 416.164(a)(4) packages every other drug into the facility payment. Chapter 14, section 40 says they are paid as under OPPS.

The October 2026 transmittal says most non-pass-through drugs and biologicals are paid at ASP plus 6 percent, refreshed quarterly in Addendum BB. A new drug with no product-specific code goes on HCPCS C9399 and is contractor-priced at 95 percent of average wholesale price (Chapter 14, section 40).

Three newer rules add lines once packaged. Under 42 CFR 416.174, a qualifying non-opioid drug, biological or device for post-surgical pain is separately paid from January 1, 2025 through December 31, 2027. HCPCS C9812 was updated effective April 30, 2026 to include Stimuplex needles. Skin substitutes use indicator S2.

Ancillary lines must ride on the same claim as the surgery. Section 40 says an ancillary item sent alone is checked against history for an approved ASC procedure on that date and is returned as unprocessable if none exists. Block codes are on pain management billing.

How do we split professional and facility billing?

The surgeon's fee goes to the physician and the facility fee goes to the ASC (Chapter 14, section 30), on separately priced claims.

Some services done in an ASC are not ASC facility services. Chapter 14, section 10.3 lists physician services, take-home durable medical equipment, ambulance and independent laboratory work. A procedure that is not on the ASC list is a different case: the same section says the ASC bills the beneficiary for its facility charges.

What is ASC quality reporting and what happens if we skip it?

The ASC Quality Reporting (ASCQR) Program cuts an ASC's annual payment update by 2.0 percentage points when it fails to report. 42 CFR 416.171(a)(2)(vi) and (vii) set the cut for CY 2019 through 2026 and for CY 2027 onward.

Confirm the active measure list for your year on QualityNet before each deadline.

What are the most common ASC denials?

Most ASC denials follow the payment indicator, and Chapter 14, section 60.3 fixes the remittance codes for each. Timely filing is the other hard stop: 42 CFR 424.44 sets one calendar year from the date of service for Medicare.

How do we handle ASC billing?

We build the ASC claim around the payment indicator, not the other way round. Coders check each code against the current addendum, apply 73, 74, FB and FC from the operative report and implant log, and keep packaged items off separate lines. Claims are sent within 24 hours of charge entry, and denials are worked within 48 hours.

For hospital-owned centers we also prepare the UB-04 side, and for surgeons the professional claim on the CMS-1500, inside your EHR. To see how this would work for you, book a call.