HCPCS L5590: Above-Knee/Knee-Disarticulation Ischial-Level Socket, Non-Alignable

HCPCS Level II code L5590 describes a preparatory above-knee / knee-disarticulation ischial-level prosthetic socket built as a non-alignable system with a pylon (no cover), SACH foot, laminated socket molded to a model; service type: prosthetic fabrication and assembly for a transfemoral or knee-disarticulation prosthesis; typical site of service: outpatient prosthetics clinic or orthotics and prosthetics facility where custom sockets and prosthetic components are fabricated and fitted.

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HCPCS L5590: Above-Knee/Knee-Disarticulation Ischial-Level Socket, Non-Alignable

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Clinical & Coding Specifications

Clinical Context

A 58-year-old male with a history of peripheral arterial disease and chronic non-healing right lower-extremity wounds undergoes a transfemoral (above-knee) amputation at the distal femur/knee-disarticulation level. After surgical healing and residual limb stabilization, the patient is evaluated by a prosthetist in an outpatient orthotics and prosthetics clinic for fabrication of a preparatory above-knee (knee-disarticulation/ischial-level) socket prosthesis. The service described by L5590 is for a non-alignable system with a laminated socket, pylon without cover, and a SACH foot; the socket is molded to a positive model.

The clinical workflow includes:

Referral from the surgical team or physical medicine and rehabilitation physician to a certified prosthetist.
A prosthetic evaluation visit to assess limb volume, skin integrity, range of motion, strength, functional goals, and gait potential.
Casting or scanning of the residual limb and fabrication of a laminated socket molded to the model as the preparatory device.
Alignment and bench fitting with the pylon and SACH foot attached; initial adjustments for comfort and suspension.
Follow-up visits for fitting adjustments, gait training with a physical therapist, and documentation of functional progress.
Typical site of service: outpatient prosthetics clinic, orthotics and prosthetics facility, or hospital outpatient department for prosthetic fabrication and fitting.
Typical patient scenario: post-amputation rehabilitation phase requiring a preparatory prosthesis to enable early mobility, limb shaping, and progression toward a definitive, alignable prosthetic system.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`97760`	Orthotic management and training, initial encounter (including assessment and fit, with training in use of device)	Used for prosthetic training and functional mobility instruction after delivery of the preparatory prosthesis.
`97763`	Assistive technology evaluation(s) (e.g., seating, positioning, mobility device), initial or follow-up	Used when a comprehensive mobility-device evaluation is performed to determine appropriate prosthetic components and functional needs.
`11720`	Debridement of nail(s) or `99070`	Data not provided in the input.

Related Modifiers

5 rows

Modifier	Description	When to Use
52	Modifier ‑52 (Reduced Services) indicates that a service or procedure was partially reduced or omitted at the provider’s discretion, allowing reporting of the basic procedure number with a qualifier…	- Use modifier -52 when a physician or qualified health professional electively reduces or omits part of a procedure or service (for example, performing fewer required views or omitting a portion of…
59	Modifier 59 indicates a distinct procedural service when two procedures that are not normally billed together are clinically and procedurally separate. The CPT definition (as reiterated by CMS)…	- Use modifier -59 to report a distinct procedural service when documentation supports that the procedure reported is not normally billed together with another service on the same day because of a…
80	CPT® Modifier 80 (Assistant Surgeon) is appended to a surgical CPT code when a physician (MD or DO) provides full, continuous assistance throughout the operative procedure. It is intended only for…	- Use CPT Modifier -80 when a physician (MD or DO) serves as an assistant surgeon and provides full, continuous assistance throughout the entire operative procedure; append -80 to the surgical CPT…
62	Modifier 62 indicates that two surgeons function as co‑surgeons, each performing distinct parts of the same primary surgical procedure. It is appended to the primary procedure code (and any…	- Use modifier -62 when two surgeons act as co‑surgeons (both primary surgeons) on a single definitive primary procedure, each performing distinct parts of the same surgical procedure (append -62 to…
78	CPT modifier -78 indicates an unplanned, related return to the operating or procedure room by the same provider during the global postoperative period. It is appended when treatment for a…	- Use modifier -78 when an unplanned, related complication during the original procedure’s global postoperative period requires the patient to return to a formal operating or procedure room and the…

Related Provider Taxonomies

8 rows

Taxonomy Code	Specialty	Notes
207L00000X	Anesthesiology Physician	An anesthesiologist is trained to provide pain relief and maintenance, or restoration, of a stable condition during and immediately following an opera…
2080P0206X	Pediatric Gastroenterology Physician	A pediatrician who specializes in the diagnosis and treatment of diseases of the digestive systems of infants, children and adolescents. This speciali…
207P00000X	Emergency Medicine Physician	An emergency physician focuses on the immediate decision making and action necessary to prevent death or any further disability both in the pre-hospit…
208000000X	Pediatrics Physician	A pediatrician is concerned with the physical, emotional and social health of children from birth to young adulthood. Care encompasses a broad spectru…
207R00000X	Internal Medicine Physician	A physician who provides long-term, comprehensive care in the office and the hospital, managing both common and complex illness of adolescents, adults…
163WI0500X	Infusion Therapy Registered Nurse	Nursing Service Providers · Registered Nurse
207W00000X	Ophthalmology Physician	An ophthalmologist has the knowledge and professional skills needed to provide comprehensive eye and vision care. Ophthalmologists are medically train…
163WX0200X	Oncology Registered Nurse	Nursing Service Providers · Registered Nurse

Related ICD-10-CM Codes

24 rows

ICD-10-CM Code	Description
E10.621	Type 1 diabetes mellitus with foot ulcer
E11.621	Type 2 diabetes mellitus with foot ulcer
F03.90	Unspecified dementia, unspecified severity, without behavioral disturbance, psychotic disturbance, mood disturbance, and anxiety
G62.9	Polyneuropathy, unspecified
I70.231	Atherosclerosis of native arteries of right leg with ulceration of thigh
I70.233	Atherosclerosis of native arteries of right leg with ulceration of ankle
I96	Gangrene, not elsewhere classified
L97.411	Non-pressure chronic ulcer of right heel and midfoot limited to breakdown of skin
L97.412	Non-pressure chronic ulcer of right heel and midfoot with fat layer exposed
L97.419	Non-pressure chronic ulcer of right heel and midfoot with unspecified severity

Showing 1–10 of 24

HCPCS Level II L5000: Partial Foot Shoe Insert with Longitudinal Arch, Toe Filler

HCPCS-L5010-PARTIAL-FOOT-MOLDED-SOCKET-ANKLE-HEIGHT-TOE-FILLER

HCPCS L5010: Partial Foot Molded Socket, Ankle Height, With Toe Filler

HCPCS-L5020-PARTIAL-FOOT-MOLDED-SOCKET-TIBIAL-TUBERCLE-TOE-FILLER

HCPCS L5020: Partial Foot Molded Socket with Toe Filler

HCPCS-L5050-ANKLE-SYMES-MOLDED-SOCKET-SACH-FOOT

HCPCS L5050: Ankle/Symes Molded Socket with SACH Foot

HCPCS-L5060-ANKLE-SYMES-METAL-FRAME-MOLDED-LEATHER-SOCKET-ARTICULATED-ANKLE-FOOT

HCPCS L5060: Ankle/Symes Metal Frame with Molded Leather Socket

HCPCS-L5100-BELOW-KNEE-MOLDED-SOCKET-SHIN-SACH-FOOT

HCPCS Level II L5100: Below-Knee Molded Socket with Shin and SACH Foot

HCPCS-L5105-BELOW-KNEE-PLASTIC-SOCKET-SACH-FOOT

HCPCS L5105: Below-Knee Plastic Socket Prosthesis with SACH Foot

HCPCS-L5150-KNEE-DISARTICULATION-MOLDED-SOCKET-EXTERNAL-KNEE-SACH-FOOT

HCPCS L5150: Knee Disarticulation Molded Socket with External Knee and SACH Foot

HCPCS-L5160-KNEE-DISARTICULATION-MOLDED-SOCKET-BENT-KNEE-SACH-FOOT

HCPCS Level II L5160: Knee Disarticulation Molded Socket, Bent Knee Configuration

HCPCS-L5200-ABOVE-KNEE-MOLDED-SOCKET-SINGLE-AXIS-KNEE-SACH-FOOT

HCPCS Level II L5200: Above-knee Prosthesis with Molded Socket and Single-axis Knee

Showing 1–10 of 472

Frequently Asked Questions

References

1.CPT® Codes and Descriptions. AAPC. Retrieved Aug 11, 2026.Maintains the CPT code set's official descriptions and guidelines, licensed from the American Medical Association, used as the definitional source for CPT codes on this page.
2.HCPCS Quarterly Update. Centers for Medicare & Medicaid Services (CMS). Retrieved Aug 11, 2026.CMS's quarterly release of HCPCS Level II codes and short/long descriptors, the source for HCPCS code definitions and update history.
3.ICD-10-CM Full Code List. Centers for Medicare & Medicaid Services (CMS). Retrieved Aug 11, 2026.CMS's complete ICD-10-CM diagnosis code list, used to cross-reference diagnosis codes associated with this procedure or service.

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Clinical & Coding Specifications

Clinical Context

The clinical workflow includes:

Referral from the surgical team or physical medicine and rehabilitation physician to a certified prosthetist.
A prosthetic evaluation visit to assess limb volume, skin integrity, range of motion, strength, functional goals, and gait potential.
Casting or scanning of the residual limb and fabrication of a laminated socket molded to the model as the preparatory device.
Alignment and bench fitting with the pylon and SACH foot attached; initial adjustments for comfort and suspension.
Follow-up visits for fitting adjustments, gait training with a physical therapist, and documentation of functional progress.
Typical site of service: outpatient prosthetics clinic, orthotics and prosthetics facility, or hospital outpatient department for prosthetic fabrication and fitting.
Typical patient scenario: post-amputation rehabilitation phase requiring a preparatory prosthesis to enable early mobility, limb shaping, and progression toward a definitive, alignable prosthetic system.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`97760`	Orthotic management and training, initial encounter (including assessment and fit, with training in use of device)	Used for prosthetic training and functional mobility instruction after delivery of the preparatory prosthesis.
`97763`	Assistive technology evaluation(s) (e.g., seating, positioning, mobility device), initial or follow-up	Used when a comprehensive mobility-device evaluation is performed to determine appropriate prosthetic components and functional needs.
`11720`	Debridement of nail(s) or `99070`	Data not provided in the input.

Related Modifiers

5 rows

Modifier	Description	When to Use
52	Modifier ‑52 (Reduced Services) indicates that a service or procedure was partially reduced or omitted at the provider’s discretion, allowing reporting of the basic procedure number with a qualifier…	- Use modifier -52 when a physician or qualified health professional electively reduces or omits part of a procedure or service (for example, performing fewer required views or omitting a portion of…
59	Modifier 59 indicates a distinct procedural service when two procedures that are not normally billed together are clinically and procedurally separate. The CPT definition (as reiterated by CMS)…	- Use modifier -59 to report a distinct procedural service when documentation supports that the procedure reported is not normally billed together with another service on the same day because of a…
80	CPT® Modifier 80 (Assistant Surgeon) is appended to a surgical CPT code when a physician (MD or DO) provides full, continuous assistance throughout the operative procedure. It is intended only for…	- Use CPT Modifier -80 when a physician (MD or DO) serves as an assistant surgeon and provides full, continuous assistance throughout the entire operative procedure; append -80 to the surgical CPT…
62	Modifier 62 indicates that two surgeons function as co‑surgeons, each performing distinct parts of the same primary surgical procedure. It is appended to the primary procedure code (and any…	- Use modifier -62 when two surgeons act as co‑surgeons (both primary surgeons) on a single definitive primary procedure, each performing distinct parts of the same surgical procedure (append -62 to…
78	CPT modifier -78 indicates an unplanned, related return to the operating or procedure room by the same provider during the global postoperative period. It is appended when treatment for a…	- Use modifier -78 when an unplanned, related complication during the original procedure’s global postoperative period requires the patient to return to a formal operating or procedure room and the…

Related Provider Taxonomies

8 rows

Taxonomy Code	Specialty	Notes
207L00000X	Anesthesiology Physician	An anesthesiologist is trained to provide pain relief and maintenance, or restoration, of a stable condition during and immediately following an opera…
2080P0206X	Pediatric Gastroenterology Physician	A pediatrician who specializes in the diagnosis and treatment of diseases of the digestive systems of infants, children and adolescents. This speciali…
207P00000X	Emergency Medicine Physician	An emergency physician focuses on the immediate decision making and action necessary to prevent death or any further disability both in the pre-hospit…
208000000X	Pediatrics Physician	A pediatrician is concerned with the physical, emotional and social health of children from birth to young adulthood. Care encompasses a broad spectru…
207R00000X	Internal Medicine Physician	A physician who provides long-term, comprehensive care in the office and the hospital, managing both common and complex illness of adolescents, adults…
163WI0500X	Infusion Therapy Registered Nurse	Nursing Service Providers · Registered Nurse
207W00000X	Ophthalmology Physician	An ophthalmologist has the knowledge and professional skills needed to provide comprehensive eye and vision care. Ophthalmologists are medically train…
163WX0200X	Oncology Registered Nurse	Nursing Service Providers · Registered Nurse

Related ICD-10-CM Codes

24 rows

ICD-10-CM Code	Description
E10.621	Type 1 diabetes mellitus with foot ulcer
E11.621	Type 2 diabetes mellitus with foot ulcer
F03.90	Unspecified dementia, unspecified severity, without behavioral disturbance, psychotic disturbance, mood disturbance, and anxiety
G62.9	Polyneuropathy, unspecified
I70.231	Atherosclerosis of native arteries of right leg with ulceration of thigh
I70.233	Atherosclerosis of native arteries of right leg with ulceration of ankle
I96	Gangrene, not elsewhere classified
L97.411	Non-pressure chronic ulcer of right heel and midfoot limited to breakdown of skin
L97.412	Non-pressure chronic ulcer of right heel and midfoot with fat layer exposed
L97.419	Non-pressure chronic ulcer of right heel and midfoot with unspecified severity

Showing 1–10 of 24

HCPCS Level II L5000: Partial Foot Shoe Insert with Longitudinal Arch, Toe Filler

HCPCS-L5010-PARTIAL-FOOT-MOLDED-SOCKET-ANKLE-HEIGHT-TOE-FILLER

HCPCS L5010: Partial Foot Molded Socket, Ankle Height, With Toe Filler

HCPCS-L5020-PARTIAL-FOOT-MOLDED-SOCKET-TIBIAL-TUBERCLE-TOE-FILLER

HCPCS L5020: Partial Foot Molded Socket with Toe Filler

HCPCS-L5050-ANKLE-SYMES-MOLDED-SOCKET-SACH-FOOT

HCPCS L5050: Ankle/Symes Molded Socket with SACH Foot

HCPCS-L5060-ANKLE-SYMES-METAL-FRAME-MOLDED-LEATHER-SOCKET-ARTICULATED-ANKLE-FOOT

HCPCS L5060: Ankle/Symes Metal Frame with Molded Leather Socket

HCPCS-L5100-BELOW-KNEE-MOLDED-SOCKET-SHIN-SACH-FOOT

HCPCS Level II L5100: Below-Knee Molded Socket with Shin and SACH Foot

HCPCS-L5105-BELOW-KNEE-PLASTIC-SOCKET-SACH-FOOT

HCPCS L5105: Below-Knee Plastic Socket Prosthesis with SACH Foot

HCPCS-L5150-KNEE-DISARTICULATION-MOLDED-SOCKET-EXTERNAL-KNEE-SACH-FOOT

HCPCS L5150: Knee Disarticulation Molded Socket with External Knee and SACH Foot

HCPCS-L5160-KNEE-DISARTICULATION-MOLDED-SOCKET-BENT-KNEE-SACH-FOOT

HCPCS Level II L5160: Knee Disarticulation Molded Socket, Bent Knee Configuration

HCPCS-L5200-ABOVE-KNEE-MOLDED-SOCKET-SINGLE-AXIS-KNEE-SACH-FOOT

HCPCS Level II L5200: Above-knee Prosthesis with Molded Socket and Single-axis Knee

Showing 1–10 of 472

Frequently Asked Questions

References

1.CPT® Codes and Descriptions. AAPC. Retrieved Aug 11, 2026.Maintains the CPT code set's official descriptions and guidelines, licensed from the American Medical Association, used as the definitional source for CPT codes on this page.
2.HCPCS Quarterly Update. Centers for Medicare & Medicaid Services (CMS). Retrieved Aug 11, 2026.CMS's quarterly release of HCPCS Level II codes and short/long descriptors, the source for HCPCS code definitions and update history.
3.ICD-10-CM Full Code List. Centers for Medicare & Medicaid Services (CMS). Retrieved Aug 11, 2026.CMS's complete ICD-10-CM diagnosis code list, used to cross-reference diagnosis codes associated with this procedure or service.

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Trek Health powers OpenPayer with a leading commercial payer intelligence platform, seamlessly converting fragmented payer data into actionable insights for provider organizations.

OpenPayer

HCPCS L5590: Above-Knee/Knee-Disarticulation Ischial-Level Socket, Non-Alignable

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OpenPayer

HCPCS L5590: Above-Knee/Knee-Disarticulation Ischial-Level Socket, Non-Alignable

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Clinical & Coding Specifications

Clinical Context

Related CPT Codes

Related Modifiers

Related Provider Taxonomies

Related ICD-10-CM Codes

Related Codes

References

Clinical & Coding Specifications

Clinical Context

Related CPT Codes

Related Modifiers

Related Provider Taxonomies

Related ICD-10-CM Codes

Related Codes

References

HCPCS L5590: Above-Knee/Knee-Disarticulation Ischial-Level Socket, Non-Alignable

Sign up for hcpcs L5590 policy alerts

HCPCS L5590: Above-Knee/Knee-Disarticulation Ischial-Level Socket, Non-Alignable

Sign up for hcpcs L5590 policy alerts

Clinical & Coding Specifications

Clinical Context

Related CPT Codes

Related Modifiers

Related Provider Taxonomies

Related ICD-10-CM Codes

Related Codes

What does HCPCS code L5590 represent?

Where and in what clinical workflow is L5590 typically provided?

Which modifiers apply to billing L5590 and when are they used?

Which ICD-10 diagnosis codes are commonly associated with claims for L5590?

What related CPT codes should be considered alongside L5590?

References

Clinical & Coding Specifications

Clinical Context

Related CPT Codes

Related Modifiers

Related Provider Taxonomies

Related ICD-10-CM Codes

Related Codes

What does HCPCS code L5590 represent?

Where and in what clinical workflow is L5590 typically provided?

Which modifiers apply to billing L5590 and when are they used?

Which ICD-10 diagnosis codes are commonly associated with claims for L5590?

What related CPT codes should be considered alongside L5590?

References