CPT 29871: Arthroscopic Irrigation and Drainage of Knee Joint

Medicare pays $502 on average nationally for this procedure.

CPT code 29871 describes an arthroscopic procedure in which the provider inspects the intra-articular tissues of the knee with an arthroscope to evaluate a suspected infection, performs joint irrigation (washout), and drains purulent material; service type: arthroscopic diagnostic and therapeutic debridement/irrigation; typical site of service: operating room or ambulatory surgery center for knee joint irrigation and drainage.

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CPT 29871: Arthroscopic Irrigation and Drainage of Knee Joint

Medicare pays $502 on average nationally for this procedure.

Customize your policy alerts

Sign up for cpt 29871 policy alerts

Get alerted when payer policies referencing 29871 are released or updated.

Monitor payer policy activity

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Clinical & Coding Specifications

Clinical Context

A typical patient is an adult who presents to the emergency department or orthopaedic clinic with acute onset knee pain, swelling, fever, and limited range of motion suspicious for septic arthritis. The patient often has elevated inflammatory markers (e.g., ESR, CRP), joint effusion on physical exam and ultrasound, and synovial fluid aspiration that is purulent or shows a high white blood cell count. After initial evaluation and attempted aspiration, the orthopaedic surgeon schedules an arthroscopic irrigation and debridement of the knee to inspect the intra-articular structures, obtain intraoperative cultures, wash out purulent material, and place drains if indicated.

The clinical workflow includes preoperative evaluation (history, focused exam, labs, and imaging), informed consent, administration of antibiotics per institutional protocol (often after cultures obtained when possible), operating room arthroscopy under regional or general anesthesia, synovial biopsy/culture collection, arthroscopic lavage and debridement, possible placement of a drain, postoperative monitoring for infection control, and coordination with infectious disease for targeted antimicrobial therapy and follow-up care. Typical site of service is the hospital operating room; ambulatory surgical center use is less common for acute septic presentations.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`29870`	Arthroscopy, knee, diagnostic, with or without synovial biopsy (separate procedure)	Often performed immediately prior to or combined with `29871` when primary goal is diagnostic inspection and biopsy.
`29872`	Arthroscopy, knee, with removal of loose body(ies)	May be performed during the same session if loose bodies are found while performing irrigation and debridement.
`29875`	Arthroscopy, knee, synovectomy (major)	May be performed in addition to irrigation/debridement for extensive synovial disease or infection requiring synovectomy.
`20650`	Arthrocentesis, aspiration and/or injection, major joint or bursa (e.g., knee)	Often performed preoperatively for diagnostic aspiration; may be billed separately if performed in clinic prior to OR.
`10180`	Incision and drainage, complex (e.g., deep abscess)	May be used if a separate open irrigation and drainage is required in addition to arthroscopic washout.

Related Modifiers

8 rows

Modifier	Description	When to Use
22	Modifier –22 (Increased Procedural Services) is used when a reported procedure is substantially more extensive than normally required. The CPT Manual and CMS state it may be appended only when the…	- When to use: Append modifier -22 to a procedural CPT code when the service performed is substantially more extensive than the usual service described by that code — i.e., the procedure required…
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…
53	Modifier 53 (Discontinued Procedure) signals that a surgical or diagnostic service was begun by the physician but terminated because of extenuating circumstances that threatened the patient’s…	- Use modifier -53 when a physician/qualified healthcare professional has started a surgical or diagnostic procedure (e.g., anesthesia administered, incision or scope insertion) and then discontinues…
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…
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…
63	Modifier‑63 is appended to surgical CPT codes (20000–69990) when a procedure is performed on a neonate or infant weighing ≤ 4 kg (about 8.8 lbs). The AMA/AAPC definition specifies this use and notes…	- Use modifier -63 only for surgical procedures in the CPT 20000–69990 series performed on a neonate or infant who weighs ≤ 4 kg at the time of the procedure; it indicates increased complexity due 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…
79	Modifier 79 indicates a surgical procedure performed during the postoperative global period of a prior surgery that is unrelated to the original procedure. Per AMA/CPT and CMS guidance, it is…	- Use modifier 79 when the same physician (or same‑specialty physician in the same group) performs a surgical procedure during the postoperative global period of a prior surgery and the new procedure…

Related Provider Taxonomies

8 rows

Taxonomy Code	Specialty	Notes
207X00000X	Orthopaedic Surgery Physician	An orthopaedic surgeon is trained in the preservation, investigation and restoration of the form and function of the extremities, spine and associated…
2080P0208X	Pediatric Infectious Diseases Physician	A pediatrician trained to care for children in the diagnosis, treatment and prevention of infectious diseases. This specialist can apply specific know…
207K00000X	Allergy & Immunology Physician	An allergist-immunologist is trained in evaluation, physical and laboratory diagnosis, and management of disorders involving the immune system. Select…
207LP2900X	Pain Medicine (Anesthesiology) Physician	An anesthesiologist who provides a high level of care, either as a primary physician or consultant, for patients experiencing problems with acute, chr…
364SN0800X	Neuroscience Clinical Nurse Specialist	Physician Assistants & Advanced Practice Nursing Providers · Clinical Nurse Specialist
2084P2900X	Pain Medicine (Psychiatry & Neurology) Physician	A neurologist, child neurologists or psychiatrist who provides a high level of care, either as a primary physician or consultant, for patients experie…
243U00000X	Radiology Practitioner Assistant	A Radiology Practitioner Assistant (RPA) is a health professional certified as a registered radiographer with the American Registry of Radiologic Tech…
133V00000X	Registered Dietitian	A Registered Dietitian (RD)/Registered Dietitian Nutritionist (RDN) is an individual uniquely trained in the science of nutrition and practice of diet…

Related ICD-10-CM Codes

22 rows

ICD-10-CM Code	Description
A52.11	Tabes dorsalis
M00.061	Staphylococcal arthritis, right knee
M00.062	Staphylococcal arthritis, left knee
M00.071	Staphylococcal arthritis, right ankle and foot
M00.072	Staphylococcal arthritis, left ankle and foot
M00.169	Pneumococcal arthritis, unspecified knee
M00.261	Other streptococcal arthritis, right knee
M00.269	Other streptococcal arthritis, unspecified knee
M17.0	Bilateral primary osteoarthritis of knee
M17.11	Unilateral primary osteoarthritis, right knee

Showing 1–10 of 22

Related Payer Policy Updates

Specialty: Anesthesiology1 / 3

10 rows

Policy	Payer	Effective Date
Intravenous Anesthetics for the Treatment of Chronic Pain and Psychiatric or Substance Use Disorders	Premera Bluecross	2026-07-01
Intravenous Anesthetics for the Treatment of Chronic Pain and Psychiatric or Substance Use Disorders	Premera Bluecross	2026-07-01
Intravenous Anesthetics for the Treatment of Chronic Pain and Psychiatric or Substance Use Disorders	Premera Bluecross	2026-07-01
Intravenous Anesthetics for the Treatment of Chronic Pain and Psychiatric or Substance Use Disorders	Premera Bluecross	2026-07-01
Elective Inpatient Services (for Idaho Only)	UnitedHealthcare	2026-06-01
Sites of Service	priority health	2026-06-01
Coverage for Ambulatory Surgery Unit (ASU)/Outpatient Facility and Anesthesia for Dental Services	univerahealthcare	2026-05-21
Mm_0579_Coveragepositioncriteria_Anesthesia_Services_Selected_Nerve_Blocks	Cigna	2026-05-15
Intravenous Anesthetics for the Treatment of Chronic Pain and Psychiatric Disorders	Blue Cross Blue Shield - North Carolina	2026-04-01
Intravenous Anesthetics for the Treatment of Chronic Pain and Psychiatric Disorders	Blue Cross Blue Shield - North Carolina	2026-04-01

CPT 29800: Temporomandibular Joint Arthroscopy, Diagnostic

CPT-29804-TEMPOROMANDIBULAR-JOINT-ARTHROSCOPY-TMJ-REPAIR

CPT 29804: Temporomandibular Joint Arthroscopy

CPT-29805-SHOULDER-ARTHROSCOPY-WITH-SYNOVIAL-BIOPSY

CPT 29805: Diagnostic Shoulder Arthroscopy with Synovial Biopsy

CPT-29806-ARTHROSCOPIC-SHOULDER-CAPSULE-REPAIR

CPT 29806: Arthroscopy, Shoulder, Repair of Capsular Tear

CPT-29807-ARTHROSCOPIC-SLAP-LESION-REPAIR-SHOULDER

CPT 29807: Arthroscopic Repair of SLAP Lesion in Shoulder

CPT-29819-ARTHROSCOPIC-SHOULDER-LOOSE-FOREIGN-BODY-REMOVAL

CPT 29819: Arthroscopic Removal of Loose or Foreign Bodies, Shoulder

CPT-29820-ARTHROSCOPIC-SHOULDER-SYNOVECTOMY

CPT 29820: Arthroscopic Synovectomy of Shoulder

CPT-29821-ARTHROSCOPIC-SHOULDER-SYNOVECTOMY

CPT 29821: Arthroscopic Complete Synovectomy of Shoulder

CPT-29822-SHOULDER-ARTHROSCOPY-LIMITED-DEBRIDEMENT

CPT 29822: Arthroscopy, Shoulder, Limited Debridement

CPT-29823-ARTHROSCOPIC-SHOULDER-DEBRIDEMENT-EXTENSIVE-TISSUE-EXCISION

CPT 29823: Arthroscopic Shoulder Extensive Excision/Debridement

Showing 1–10 of 75

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

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`29870`	Arthroscopy, knee, diagnostic, with or without synovial biopsy (separate procedure)	Often performed immediately prior to or combined with `29871` when primary goal is diagnostic inspection and biopsy.
`29872`	Arthroscopy, knee, with removal of loose body(ies)	May be performed during the same session if loose bodies are found while performing irrigation and debridement.
`29875`	Arthroscopy, knee, synovectomy (major)	May be performed in addition to irrigation/debridement for extensive synovial disease or infection requiring synovectomy.
`20650`	Arthrocentesis, aspiration and/or injection, major joint or bursa (e.g., knee)	Often performed preoperatively for diagnostic aspiration; may be billed separately if performed in clinic prior to OR.
`10180`	Incision and drainage, complex (e.g., deep abscess)	May be used if a separate open irrigation and drainage is required in addition to arthroscopic washout.

Related Modifiers

8 rows

Modifier	Description	When to Use
22	Modifier –22 (Increased Procedural Services) is used when a reported procedure is substantially more extensive than normally required. The CPT Manual and CMS state it may be appended only when the…	- When to use: Append modifier -22 to a procedural CPT code when the service performed is substantially more extensive than the usual service described by that code — i.e., the procedure required…
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…
53	Modifier 53 (Discontinued Procedure) signals that a surgical or diagnostic service was begun by the physician but terminated because of extenuating circumstances that threatened the patient’s…	- Use modifier -53 when a physician/qualified healthcare professional has started a surgical or diagnostic procedure (e.g., anesthesia administered, incision or scope insertion) and then discontinues…
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…
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…
63	Modifier‑63 is appended to surgical CPT codes (20000–69990) when a procedure is performed on a neonate or infant weighing ≤ 4 kg (about 8.8 lbs). The AMA/AAPC definition specifies this use and notes…	- Use modifier -63 only for surgical procedures in the CPT 20000–69990 series performed on a neonate or infant who weighs ≤ 4 kg at the time of the procedure; it indicates increased complexity due 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…
79	Modifier 79 indicates a surgical procedure performed during the postoperative global period of a prior surgery that is unrelated to the original procedure. Per AMA/CPT and CMS guidance, it is…	- Use modifier 79 when the same physician (or same‑specialty physician in the same group) performs a surgical procedure during the postoperative global period of a prior surgery and the new procedure…

Related Provider Taxonomies

8 rows

Taxonomy Code	Specialty	Notes
207X00000X	Orthopaedic Surgery Physician	An orthopaedic surgeon is trained in the preservation, investigation and restoration of the form and function of the extremities, spine and associated…
2080P0208X	Pediatric Infectious Diseases Physician	A pediatrician trained to care for children in the diagnosis, treatment and prevention of infectious diseases. This specialist can apply specific know…
207K00000X	Allergy & Immunology Physician	An allergist-immunologist is trained in evaluation, physical and laboratory diagnosis, and management of disorders involving the immune system. Select…
207LP2900X	Pain Medicine (Anesthesiology) Physician	An anesthesiologist who provides a high level of care, either as a primary physician or consultant, for patients experiencing problems with acute, chr…
364SN0800X	Neuroscience Clinical Nurse Specialist	Physician Assistants & Advanced Practice Nursing Providers · Clinical Nurse Specialist
2084P2900X	Pain Medicine (Psychiatry & Neurology) Physician	A neurologist, child neurologists or psychiatrist who provides a high level of care, either as a primary physician or consultant, for patients experie…
243U00000X	Radiology Practitioner Assistant	A Radiology Practitioner Assistant (RPA) is a health professional certified as a registered radiographer with the American Registry of Radiologic Tech…
133V00000X	Registered Dietitian	A Registered Dietitian (RD)/Registered Dietitian Nutritionist (RDN) is an individual uniquely trained in the science of nutrition and practice of diet…

Related ICD-10-CM Codes

22 rows

ICD-10-CM Code	Description
A52.11	Tabes dorsalis
M00.061	Staphylococcal arthritis, right knee
M00.062	Staphylococcal arthritis, left knee
M00.071	Staphylococcal arthritis, right ankle and foot
M00.072	Staphylococcal arthritis, left ankle and foot
M00.169	Pneumococcal arthritis, unspecified knee
M00.261	Other streptococcal arthritis, right knee
M00.269	Other streptococcal arthritis, unspecified knee
M17.0	Bilateral primary osteoarthritis of knee
M17.11	Unilateral primary osteoarthritis, right knee

Showing 1–10 of 22

Related Payer Policy Updates

Specialty: Anesthesiology1 / 3

10 rows

Policy	Payer	Effective Date
Intravenous Anesthetics for the Treatment of Chronic Pain and Psychiatric or Substance Use Disorders	Premera Bluecross	2026-07-01
Intravenous Anesthetics for the Treatment of Chronic Pain and Psychiatric or Substance Use Disorders	Premera Bluecross	2026-07-01
Intravenous Anesthetics for the Treatment of Chronic Pain and Psychiatric or Substance Use Disorders	Premera Bluecross	2026-07-01
Intravenous Anesthetics for the Treatment of Chronic Pain and Psychiatric or Substance Use Disorders	Premera Bluecross	2026-07-01
Elective Inpatient Services (for Idaho Only)	UnitedHealthcare	2026-06-01
Sites of Service	priority health	2026-06-01
Coverage for Ambulatory Surgery Unit (ASU)/Outpatient Facility and Anesthesia for Dental Services	univerahealthcare	2026-05-21
Mm_0579_Coveragepositioncriteria_Anesthesia_Services_Selected_Nerve_Blocks	Cigna	2026-05-15
Intravenous Anesthetics for the Treatment of Chronic Pain and Psychiatric Disorders	Blue Cross Blue Shield - North Carolina	2026-04-01
Intravenous Anesthetics for the Treatment of Chronic Pain and Psychiatric Disorders	Blue Cross Blue Shield - North Carolina	2026-04-01

CPT 29800: Temporomandibular Joint Arthroscopy, Diagnostic

CPT-29804-TEMPOROMANDIBULAR-JOINT-ARTHROSCOPY-TMJ-REPAIR

CPT 29804: Temporomandibular Joint Arthroscopy

CPT-29805-SHOULDER-ARTHROSCOPY-WITH-SYNOVIAL-BIOPSY

CPT 29805: Diagnostic Shoulder Arthroscopy with Synovial Biopsy

CPT-29806-ARTHROSCOPIC-SHOULDER-CAPSULE-REPAIR

CPT 29806: Arthroscopy, Shoulder, Repair of Capsular Tear

CPT-29807-ARTHROSCOPIC-SLAP-LESION-REPAIR-SHOULDER

CPT 29807: Arthroscopic Repair of SLAP Lesion in Shoulder

CPT-29819-ARTHROSCOPIC-SHOULDER-LOOSE-FOREIGN-BODY-REMOVAL

CPT 29819: Arthroscopic Removal of Loose or Foreign Bodies, Shoulder

CPT-29820-ARTHROSCOPIC-SHOULDER-SYNOVECTOMY

CPT 29820: Arthroscopic Synovectomy of Shoulder

CPT-29821-ARTHROSCOPIC-SHOULDER-SYNOVECTOMY

CPT 29821: Arthroscopic Complete Synovectomy of Shoulder

CPT-29822-SHOULDER-ARTHROSCOPY-LIMITED-DEBRIDEMENT

CPT 29822: Arthroscopy, Shoulder, Limited Debridement

CPT-29823-ARTHROSCOPIC-SHOULDER-DEBRIDEMENT-EXTENSIVE-TISSUE-EXCISION

CPT 29823: Arthroscopic Shoulder Extensive Excision/Debridement

Showing 1–10 of 75

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.

Published by

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

OpenPayer

CPT 29871: Arthroscopic Irrigation and Drainage of Knee Joint

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OpenPayer

CPT 29871: Arthroscopic Irrigation and Drainage of Knee Joint

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Clinical & Coding Specifications

Clinical Context

Related CPT Codes

Related Modifiers

Related Provider Taxonomies

Related ICD-10-CM Codes

Related Payer Policy Updates

Related Codes

References

Clinical & Coding Specifications

Clinical Context

Related CPT Codes

Related Modifiers

Related Provider Taxonomies

Related ICD-10-CM Codes

Related Payer Policy Updates

Related Codes

References

CPT 29871: Arthroscopic Irrigation and Drainage of Knee Joint

Sign up for cpt 29871 policy alerts

CPT 29871: Arthroscopic Irrigation and Drainage of Knee Joint

Sign up for cpt 29871 policy alerts

Clinical & Coding Specifications

Clinical Context

Related CPT Codes

Related Modifiers

Related Provider Taxonomies

Related ICD-10-CM Codes

Related Payer Policy Updates

Related Codes

What clinical scenarios typically indicate use of CPT 29871?

Where is CPT 29871 most commonly performed?

Which related CPT codes might be billed in conjunction with 29871?

What diagnoses align with billing CPT 29871?

What are the key intraoperative and perioperative workflow elements described for this procedure?

References

Clinical & Coding Specifications

Clinical Context

Related CPT Codes

Related Modifiers

Related Provider Taxonomies

Related ICD-10-CM Codes

Related Payer Policy Updates

Related Codes

What clinical scenarios typically indicate use of CPT 29871?

Where is CPT 29871 most commonly performed?

Which related CPT codes might be billed in conjunction with 29871?

What diagnoses align with billing CPT 29871?

What are the key intraoperative and perioperative workflow elements described for this procedure?

References