Need help choosing the right code?
Ask CasePilot about procedures, modifiers, bundling, and coding guidance.
Try CasePilot© Copyright 2026 American Medical Association. All rights reserved.
A diagnostic arthroscopy of the knee, identified by CPT® Code 29870, is a minimally invasive surgical procedure that allows for the examination of the knee joint. This procedure can be performed with or without a synovial biopsy, which involves taking a sample of the synovial tissue for further analysis. During the procedure, two small incisions, referred to as portal incisions, are made—one on the medial (inner) side and one on the lateral (outer) side of the knee joint. An arthroscope, which is a specialized instrument equipped with a camera, is inserted through one of these incisions, providing a visual representation of the internal structures of the knee on a video screen. The other incision is used to insert an irrigation cannula, which allows for the flushing of the knee joint with saline solution. This flushing process helps to clear any cloudy fluid or debris, enhancing the visibility of the joint's interior. The surgeon carefully examines the knee joint for signs of injury, disease, or other abnormalities. If necessary, synovial tissue samples are collected during the procedure and sent to a laboratory for further evaluation. Once the examination is complete, the knee is flushed again with saline, the instruments are withdrawn, and the portal incisions are closed, completing the diagnostic process.
© Copyright 2026 Coding Ahead. All rights reserved.
The diagnostic arthroscopy of the knee (CPT® Code 29870) is indicated for various conditions that may affect the knee joint. The following are explicitly provided indications for this procedure:
The procedure for a diagnostic arthroscopy of the knee involves several key steps, which are detailed as follows:
Following the diagnostic arthroscopy, patients are typically monitored for a short period to ensure there are no immediate complications. Post-procedure care may include rest, ice application to reduce swelling, and elevation of the knee. Patients are usually advised on pain management strategies and may be prescribed analgesics as needed. Follow-up appointments are often scheduled to discuss the results of any biopsies taken and to evaluate the recovery process. It is important for patients to adhere to any rehabilitation protocols recommended by their healthcare provider to ensure optimal recovery and restore knee function.
| Short Descr | KNEE ARTHROSCOPY DX | Medium Descr | ARTHROSCOPY KNEE DIAGNOSTIC W/WO SYNOVIAL BX SPX | Long Descr | Arthroscopy, knee, diagnostic, with or without synovial biopsy (separate procedure) | Status Code | Active Code | Global Days | 090 - Major Surgery | PC/TC Indicator (26, TC) | 0 - Physician Service Code | Multiple Procedures (51) | 2 - Standard payment adjustment rules for multiple procedures apply. | Bilateral Surgery (50) | 1 - 150% payment adjustment for bilateral procedures applies. | Physician Supervisions | 09 - Concept does not apply. | Assistant Surgeon (80, 82) | 1 - Statutory payment restriction for assistants at surgery applies to this procedure... | Co-Surgeons (62) | 1 - Co-surgeons could be paid, though supporting documentation is required... | Team Surgery (66) | 0 - Team surgeons not permitted for this procedure. | Diagnostic Imaging Family | 99 - Concept Does Not Apply | APC Status Indicator | Hospital Part B services paid through a comprehensive APC | ASC Payment Indicator | Surgical procedure on ASC list in CY 2007; payment based on OPPS relative payment weight. | Type of Service (TOS) | 2 - Surgery | Berenson-Eggers TOS (BETOS) | P8A - Endoscopy - arthroscopy | MUE | 1 | CCS Clinical Classification | 149 - Arthroscopy |
| 59 | Distinct procedural service: under certain circumstances, it may be necessary to indicate that a procedure or service was distinct or independent from other non-e/m services performed on the same day. modifier 59 is used to identify procedures/services, other than e/m services, that are not normally reported together, but are appropriate under the circumstances. documentation must support a different session, different procedure or surgery, different site or organ system, separate incision/excision, separate lesion, or separate injury (or area of injury in extensive injuries) not ordinarily encountered or performed on the same day by the same individual. however, when another already established modifier is appropriate it should be used rather than modifier 59. only if no more descriptive modifier is available, and the use of modifier 59 best explains the circumstances, should modifier 59 be used. note: modifier 59 should not be appended to an e/m service. to report a separate and distinct e/m service with a non-e/m service performed on the same date, see modifier 25. | LT | Left side (used to identify procedures performed on the left side of the body) | RT | Right side (used to identify procedures performed on the right side of the body) | 50 | Bilateral procedure: unless otherwise identified in the listings, bilateral procedures that are performed at the same session, should be identified by adding modifier 50 to the appropriate 5 digit code. note: this modifier should not be appended to designated "add-on" codes (see appendix d). | 51 | Multiple procedures: when multiple procedures, other than e/m services, physical medicine and rehabilitation services or provision of supplies (eg, vaccines), are performed at the same session by the same individual, the primary procedure or service may be reported as listed. the additional procedure(s) or service(s) may be identified by appending modifier 51 to the additional procedure or service code(s). note: this modifier should not be appended to designated "add-on" codes (see appendix d). | 54 | Surgical care only: when 1 physician or other qualified health care professional performs a surgical procedure and another provides preoperative and/or postoperative management, surgical services may be identified by adding modifier 54 to the usual procedure number. | 58 | Staged or related procedure or service by the same physician or other qualified health care professional during the postoperative period: it may be necessary to indicate that the performance of a procedure or service during the postoperative period was: (a) planned or anticipated (staged); (b) more extensive than the original procedure; or (c) for therapy following a surgical procedure. this circumstance may be reported by adding modifier 58 to the staged or related procedure. note: for treatment of a problem that requires a return to the operating/procedure room (eg, unanticipated clinical condition), see modifier 78. | 78 | Unplanned return to the operating/procedure room by the same physician or other qualified health care professional following initial procedure for a related procedure during the postoperative period: it may be necessary to indicate that another procedure was performed during the postoperative period of the initial procedure (unplanned procedure following initial procedure). when this procedure is related to the first, and requires the use of an operating/procedure room, it may be reported by adding modifier 78 to the related procedure. (for repeat procedures, see modifier 76.) | 79 | Unrelated procedure or service by the same physician or other qualified health care professional during the postoperative period: the individual may need to indicate that the performance of a procedure or service during the postoperative period was unrelated to the original procedure. this circumstance may be reported by using modifier 79. (for repeat procedures on the same day, see modifier 76.) | 80 | Assistant surgeon: surgical assistant services may be identified by adding modifier 80 to the usual procedure number(s). | 82 | Assistant surgeon (when qualified resident surgeon not available): the unavailability of a qualified resident surgeon is a prerequisite for use of modifier 82 appended to the usual procedure code number(s). | AS | Physician assistant, nurse practitioner, or clinical nurse specialist services for assistant at surgery | GC | This service has been performed in part by a resident under the direction of a teaching physician | Q6 | Service furnished under a fee-for-time compensation arrangement by a substitute physician or by a substitute physical therapist furnishing outpatient physical therapy services in a health professional shortage area, a medically underserved area, or a rural area | SG | Ambulatory surgical center (asc) facility service | XS | Separate structure, a service that is distinct because it was performed on a separate organ/structure | XU | Unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service |
|
Date
|
Action
|
Notes
|
|---|---|---|
| 2011-01-01 | Changed | Short description changed. |
| Pre-1990 | Added | Code added. |
Get instant expert-level medical coding assistance.