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HCPCS L3999 · Level II · orthotic and prosthetic code

L3999: Upper limb orthosis, not otherwise specified, HCPCS Level II orthotic and prosthetic 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). Next CMS release: January 1, 2027 (quarterly update).

Key facts for L3999

Medicare payment
paid outside OPPS
OPPS SI A: another fee schedule or payment system
Coverage code
C
carrier judgment, so the Medicare contractor decides coverage
Practitioner MUE
0
MAI 3
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
0 / 0

TL;DR

HCPCS Level II L3999 reads "Upper limb orthosis, not otherwise specified" in the October 2026 file; it dates from 1982. None of the October 2026 PFS, DMEPOS, CLFS, OPPS or ASC files lists a national amount for L3999; its HCPCS pricing indicator is 46 (DMEPOS contractor-priced (not otherwise classified, individual determination or gap-filled)). 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 L3999 under a fee schedule or payment system other than OPPS. MUE limits for L3999: practitioner 0 (MAI 3, CMS Policy); hospital outpatient 2 (MAI 3, Clinical: Data). No current LCD or billing article lists L3999; its HCPCS coverage code is C (carrier judgment, so the Medicare contractor decides coverage). HCPCS record: BETOS D1F (prosthetic/orthotic devices); pricing indicator 46; type of service P (lump-sum purchase of DME, prosthetics or orthotics). Nearby codes: L4000, L4002, L3995, L3984.

L3999 descriptor and code status

The October 2026 HCPCS Level II file describes L3999 as “Upper limb orthosis, not otherwise specified”. It sits in the L section (orthotic and prosthetic procedures and devices), listed with the other L codes. Although searches often call it the "L3999 CPT code", L3999 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 L3999
FieldValue
Short descriptorUpper limb orthosis nos
Added to HCPCS1982-01-01
Last actionN (no maintenance), effective 1998-01-01
Coverage codeC: carrier judgment, so the Medicare contractor decides coverage
Pricing indicator46: DMEPOS contractor-priced (not otherwise classified, individual determination or gap-filled)
BETOS categoryD1F: prosthetic/orthotic devices
Type of serviceP: lump-sum purchase of DME, prosthetics or orthotics

Medicare payment for L3999

None of the October 2026 PFS, DMEPOS, CLFS, OPPS or ASC files lists a national amount for L3999; its HCPCS pricing indicator is 46 (DMEPOS contractor-priced (not otherwise classified, individual determination or gap-filled)). 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 L3999 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.

Medically Unlikely Edits for L3999

MUE limits for L3999: practitioner 0 (MAI 3, CMS Policy); hospital outpatient 2 (MAI 3, Clinical: Data). The practitioner MUE is a date-of-service clinical edit: units above the limit deny but can be paid on appeal with documentation.

MUE values for L3999 by setting
SettingMUE (units/DOS)MAICMS rationale
Practitioner services03 Date of Service Edit: ClinicalCMS Policy
Facility outpatient hospital23 Date of Service Edit: ClinicalClinical: Data

The MUE lookup for L3999 shows every setting next to any other code on the same claim.

NCCI edits and add-on rules

No active practitioner PTP pair lists L3999 in v323r0.

L3999 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 L3999 against a second code to see whether the pair bundles and whether a modifier can separate the services.

Medicare coverage policies for L3999

No current LCD or billing and coding article lists L3999. The HCPCS coverage code C means carrier judgment, so the Medicare contractor decides coverage, and any National Coverage Determination for the service still applies.

Denials to expect on L3999

CARC 50 · N115

the service is not reasonable and necessary for the diagnosis on the claim

CARC 151 · N362

units of L3999 exceed the practitioner MUE of 0 per date of service

CARC 4

the modifier reported is inconsistent with the code

CARC 16

the claim lacks the description, invoice or pricing detail a contractor-priced code needs

Where QuickIntell fits for L3999 claims

QuickCode supports qualified coder review of units, modifiers and NCCI pairs for L3999 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 L3999

What does HCPCS code L3999 describe?

"Upper limb orthosis, not otherwise specified" (short descriptor "Upper limb orthosis nos"), in the L section (orthotic and prosthetic procedures and devices). Added 1982-01-01; last action N (no maintenance) effective 1998-01-01.

Is L3999 a CPT code?

No: CMS maintains L3999 in HCPCS Level II, while the AMA maintains CPT. People do search "L3999 CPT code", and it goes in the same procedure-code field.

What does Medicare pay for L3999?

None of the October 2026 PFS, DMEPOS, CLFS, OPPS or ASC files lists a national amount for L3999; its HCPCS pricing indicator is 46 (DMEPOS contractor-priced (not otherwise classified, individual determination or gap-filled)). 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 L3999 under a fee schedule or payment system other than OPPS.

How many units of L3999 can be billed per day?

MUE limits for L3999: practitioner 0 (MAI 3, CMS Policy); hospital outpatient 2 (MAI 3, Clinical: Data). For the practitioner MUE (MAI 3), units above 0 deny for the day but can be paid on appeal with documentation; denials arrive as CARC 151.

Does Medicare cover L3999?

No current LCD or billing article lists L3999; its HCPCS coverage code is C (carrier judgment, so the Medicare contractor decides coverage).

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.