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HCPCS C9399 · Level II · C code

C9399: Unclassified drugs or biologicals, HCPCS Level II C code

Compiled from CMS files by the QuickIntell RCM Editorial Team · Data effective · Method: reference methodology · Report a data correction

Data currency: HCPCS Level II file: October 2026 (effective October 1, 2026); NCCI MUE tables: 2026 Q4 (effective October 1, 2026); NCCI PTP edits: v323r0 (2026 Q4) (effective October 1, 2026); OPPS Addendum B: October 2026 (effective October 1, 2026); Medicare Coverage Database LCD export: MCD release October 8, 2026 (effective October 4, 2026). Next CMS release: January 1, 2027 (quarterly update) for the HCPCS Level II file and NCCI MUE tables and NCCI PTP edits and OPPS Addendum B; weekly, every Thursday for the Medicare Coverage Database LCD export.

Key facts for C9399

Medicare payment
paid outside OPPS
OPPS SI A: another fee schedule or payment system
Coverage code
D
special coverage instructions apply
MUE
none published
no MUE in the 2026 Q4 tables
OPPS status
SI A
Services not paid under OPPS; paid under fee schedule or other payment system
NCCI PTP pairs
0
practitioner file
LCDs and articles
2 / 3

TL;DR

C9399 is a Level II code from the C section (hospital outpatient prospective payment system, temporary codes), in use since 2004: "Unclassified drugs or biologicals". None of the October 2026 PFS, DMEPOS, CLFS, OPPS or ASC files lists a national amount for C9399; its HCPCS pricing indicator is 53 (statute). Its OPPS status indicator is A, which the I/OCE table defines as "Services not paid under OPPS; paid under fee schedule or other payment system": Medicare pays C9399 under a fee schedule or payment system other than OPPS. 2 active LCDs and 3 billing and coding articles list C9399 across 14 states: L33394 (Drugs and Biologicals, Coverage of, for Label and Off-Label Uses), L34338 (Transthoracic Echocardiography (TTE)), A52451, A55913. HCPCS record: BETOS O1E (other drugs); pricing indicator 53; type of service 1 (medical care). Nearby codes: C9600, C9601, C9602, C9604.

C9399 descriptor and code status

The October 2026 HCPCS Level II file describes C9399 as “Unclassified drugs or biologicals”. It sits in the C section (hospital outpatient prospective payment system, temporary codes), listed with the other C codes. Although searches often call it the "C9399 CPT code", C9399 is a HCPCS Level II code maintained by CMS, not an AMA CPT code; both go in the same procedure-code field on the claim.

HCPCS file attributes of C9399
FieldValue
Short descriptorUnclassified drugs or biolog
Added to HCPCS2004-01-01
Last actionN (no maintenance), effective 2004-01-01
Coverage codeD: special coverage instructions apply
Pricing indicator53: statute
BETOS categoryO1E: other drugs
Type of service1: medical care
Statute621MMA

Medicare payment for C9399

None of the October 2026 PFS, DMEPOS, CLFS, OPPS or ASC files lists a national amount for C9399; its HCPCS pricing indicator is 53 (statute). Its OPPS status indicator is A, which the I/OCE table defines as "Services not paid under OPPS; paid under fee schedule or other payment system": Medicare pays C9399 under a fee schedule or payment system other than OPPS. The amounts below are national figures from the October 2026 CMS files; the contractor applies the locality, rural or state adjustment and the beneficiary's cost sharing.

Hospital outpatient (OPPS Addendum B)

Status indicator A (Services not paid under OPPS; paid under fee schedule or other payment system), with no separate OPPS payment rate.

Ambulatory surgical center (Addendum BB)

Payment indicator K7 (Unclassified drugs and biologicals; payment contractor-priced).

Medically Unlikely Edits for C9399

CMS publishes no MUE for C9399 in the 2026 Q4 practitioner, facility or DME supplier tables. Some MUE values are confidential and applied without publication, so unit limits can still deny; document the quantity furnished on every claim.

The MUE lookup for C9399 shows every setting next to any other code on the same claim.

NCCI edits and add-on rules

No active practitioner PTP pair lists C9399 in v323r0.

C9399 is neither an add-on code nor a designated primary code in the 2026 Q4 NCCI add-on edit file.

Pair counts show exposure, not the answer for one claim. Check C9399 against a second code to see whether the pair bundles and whether a modifier can separate the services.

Medicare coverage policies for C9399

2 active Local Coverage Determinations and 3 billing and coding articles list C9399. Each applies only in its contractor's jurisdiction, and the article carries the diagnosis codes that support the item or service.

Billing and Coding Articles listing C9399
ArticleTitleContractor(s)Related LCD
A52451Billing and Coding: Ranibizumab, Aflibercept and biosimilarsWellpoint FederalL33394
A55913Billing and Coding: Hospital Outpatient Drugs and Biologicals Under the Outpatient Prospective Payment System (OPPS)Palmetto GBA—
A57306Billing and Coding: Transthoracic Echocardiography (TTE)CGS Administrators, LLCL34338

Denials to expect on C9399

CARC 50 · N115

the diagnosis or documentation does not meet the LCD or billing article that lists C9399

CARC 151 · N362

units exceed what the payer considers medically likely for one date of service

CARC 4

the modifier reported is inconsistent with the code

CARC 16

the claim lacks information needed to adjudicate the line, such as an order, NPI or required modifier

Where QuickIntell fits for C9399 claims

QuickCode supports qualified coder review of units, modifiers and NCCI pairs for C9399 before the claim leaves, and QuickRCM carries claim readiness and the denial follow-up when an edit or coverage policy is missed.

See QuickCode for coder reviewSee QuickRCM for denial follow-upBook a meeting

Frequently asked questions: HCPCS C9399

What does HCPCS code C9399 describe?

"Unclassified drugs or biologicals" (short descriptor "Unclassified drugs or biolog"), in the C section (hospital outpatient prospective payment system, temporary codes). Added 2004-01-01.

Is C9399 a CPT code?

It is not. C9399 belongs to the C section (hospital outpatient prospective payment system, temporary codes) of HCPCS Level II, the CMS code set, not to AMA CPT. "C9399 CPT code" searches refer to it.

What does Medicare pay for C9399?

None of the October 2026 PFS, DMEPOS, CLFS, OPPS or ASC files lists a national amount for C9399; its HCPCS pricing indicator is 53 (statute). Its OPPS status indicator is A, which the I/OCE table defines as "Services not paid under OPPS; paid under fee schedule or other payment system": Medicare pays C9399 under a fee schedule or payment system other than OPPS.

Does Medicare cover C9399?

Coverage code D (special coverage instructions apply). 2 active LCDs and 3 billing and coding articles list C9399 across 14 states: L33394 (Drugs and Biologicals, Coverage of, for Label and Off-Label Uses), L34338 (Transthoracic Echocardiography (TTE)), A52451, A55913.

Sources

Every figure on this page is taken from the CMS publications below, as released by the Centers for Medicare & Medicaid Services. Projection built 2026-10-10. Verify against the primary file before billing or contracting decisions. The reference methodology explains how each figure is computed from these files.

Disclaimer

This page is an operational reference compiled from CMS publications: the HCPCS Level II file, the physician, DMEPOS and clinical laboratory fee schedules, OPPS and ASC addenda, NCCI MUE, PTP and add-on edit tables and the Medicare Coverage Database. Amounts are Medicare national figures before locality and state adjustment; Medicaid and commercial payers set their own. CPT codes are shown as numbers only; CPT descriptors are copyright AMA. Nothing here is legal, clinical or billing advice.

Found a figure that does not match the CMS file? Report a data correction with the CMS file and the value you expected; the request reaches the editorial team through the contact form.