October 2026 ASC update (CR 14634): 10 Category III codes, drug PI moves, and two reprocessing windows

On October 8, 2026, CMS issued Transmittal R13983CP, Change Request 14634, the October 2026 update of the Ambulatory Surgical Center (ASC) payment system. It is effective October 1, 2026, by date of service unless a line says otherwise, with an implementation date of October 5, 2026. The hospital outpatient side of the same quarter is CR 14589, covered in our October 2026 OPPS update story. This piece stays on the ASC payment indicators (PIs): which new codes an ASC can bill, which drug codes moved, and which claims MACs have to go back and reprocess.

CR 14634 at a glance

Ten Category III CPT codes join the ASC list

CMS is implementing ten new Category III CPT codes, released by the AMA in early August 2026, under the ASC payment system on October 1, 2026. The OPPS update (Transmittal 13978) implements 58 new Category III codes for hospital outpatient departments; these ten are the ones Table 1 of CR 14634 assigns an ASC payment indicator.

In CMS's CY 2026 ASC payment indicator list (Addendum DD1), G2 is a non office-based surgical procedure added in CY 2008 or later, paid based on the OPPS relative payment weight, and J8 is a device-intensive procedure paid at an adjusted rate.

1091T replaces C8010. CMS created C8010 for the Category B IDE clinical study of Javelin Medical's carotid implants for permanent placement of common carotid artery filters. Because the AMA created 1091T for the same procedure effective October 1, 2026, CMS is deleting C8010, and its ASC PI is D5 (deleted or discontinued code, no payment made). CMS also revised the long descriptors for C1982, C9797 and C8004, the pressure-generating catheter codes for vascular embolization or occlusion and for simulation angiograms before radioembolization.

New and deleted drug codes for October 1

Twelve new HCPCS codes for drugs and biologicals receive pass-through status starting October 1, 2026. All twelve carry ASC PI K2, which DD1 defines as drugs, biologicals, and radiopharmaceuticals paid separately when provided integral to a surgical procedure on the ASC list, with payment based on the OPPS rate.

Ten drug codes were deleted as of September 30, 2026, all now ASC PI D5: J0640 (leucovorin calcium, per 50 mg), J1941 (furosemide (furoscix), 20 mg), J1953 (levetiracetam, 10 mg), J7514, J7517, J7519 and J7528 (mycophenolate mofetil products), J9181 (etoposide, 10 mg), J9190 (fluorouracil, 500 mg) and J9352 (trabectedin, 0.1 mg).

Watch the units. Deleted J9352 was billed per 0.1 mg of trabectedin; new J9362 is per 0.01 mg. The CR lists an old code for only one new code (J0644, old code C9310). It does not crosswalk the deleted J codes to the new product-specific codes, so check the October HCPCS file before you remap a charge line.

Table 6: 21 payment status changes, two with earlier dates

Table 6 lists 21 drug and radiopharmaceutical codes with a new ASC PI. Nineteen are effective October 1, 2026; J9161 is dated July 1, 2026 and A9521 is dated May 14, 2026. The CR's narrative describes 21 codes effective October 1 plus one effective July 1, so load from the table, not the count.

Business requirement 14634.5 describes the moves off K2 in this table as changes "to non-payable PIs." DD1 defines K5 as items, codes, and services for which pricing information and claims data are not available, with no payment made, and N1 as a packaged service or item with no separate payment. CMS also says three drug codes have substantial descriptor changes on October 1: A9595 now reads piflufolastat f 18 (pylarify), J3300 now names triamcinolone acetonide (triesence), and J9033 now reads bendamustine hydrochloride, not otherwise specified.

MACs must reprocess A9521 and J9161 claims

Two business requirements reach back into claims already processed:

• BR 14634.7. MACs shall search for and reprocess claims with dates of service from May 14, 2026 through September 30, 2026, as appropriate, that included A9521.
• BR 14634.8. MACs shall search for and reprocess claims with dates of service from July 1, 2026 through September 30, 2026, as appropriate, that included J9161.

For both, the CR says affected claims shall be reprocessed no later than 30 days of implementation of the transmittal, and the implementation date is October 5, 2026. Separately, CMS says some ASP-based drug payment rates are corrected retroactively each quarter, with the list posted on its restated drug payment rates page on the first date of the quarter, and providers may resubmit claims affected by adjustments to a previous quarter's payment files.

Skin substitutes: eight new codes, add-on wording back to April 1

DD1 defines S2 as the skin substitute supply group, paid separately when provided integral to a surgical procedure on the ASC list, with payment based on the OPPS rate. CMS is also revising the long descriptors of A2040 (Microlyte painguard), A2041 (Foundation drs+ duo), A2042 (Foundation drs+ solo), A2043 (Biobrane) and A2045 (Novashield or novogen wound matrix), retroactive to April 1, 2026, to add the parenthetical "add-on, list separately in addition to primary procedure."

Stimuplex needles added to C9812

Under Section 4135 of the Consolidated Appropriations Act, 2023, CMS determined that Stimuplex needles newly meet the statutory definition of a non-opioid treatment for pain relief, with temporary additional payment effective April 30, 2026. Rather than a new code, CMS updated the long descriptor of C9812, which now begins "Echogenic and/or nerve stimulator-guided nerve block needles (e.g. SonoPlex, SonoBlock, SonoTap, Stimuplex), nonopioid medical device," and C9812's payment indicator does not change.

CMS notes that the payment limitation is not the payment rate of the assigned APC. DD1 defines L6 as a special payment for New Technology Intraocular Lenses (NTIOL) or qualifying non-opioid devices.

Check your ASC files against the CR

The October 2026 ASC addenda zip on CMS's ASC payment rates page is dated October 1, 2026, a week before this CR. As downloaded on October 12, its Addendum BB lists J9361 and Q5154 with PI K5, while Table 6 of the CR moves both to K2 effective October 1, 2026. If your file shows K5 for those two codes, recheck the CMS addenda page for an updated file before treating the line as not payable. Check each CPT and HCPCS descriptor against the October ASC addenda, the CR 14634 transmittal (R13983CP), and the CMS October HCPCS quarterly file. For another ASC drug billing rule from this year, see our Encelto J3403 ASC billing story.

What CR 14634 does not change

It does not change manual text; the manual section of the transmittal is N/A. CMS repeats that a HCPCS code and an ASC payment rate do not imply Medicare coverage, and MACs still decide whether a drug, device, or procedure meets coverage requirements. It is not an NCCI update. CMS says national provider education will follow through the MLN Connects newsletter.