Here's your guide to success with TPI versus other knee injections. All knee injections -- and coding for them -- aren't created equal, especially when you're coding for trigger points versus a standard joint injection. Keep our experts' top advice on differentiating procedures in mind, and you'll be flexing your coding muscles with correct claims. Report TPI Based on Muscle Numbers Physicians administer trigger point injections (TPI) to treat painful muscle areas that contain trigger points, or knots of muscle that form when muscles do not relax. The most important factor when coding TPIs is to focus on the number of muscles your physician injects, not the total number of injections. Consider the descriptors for CPT®'s current TPI codes: Example: Choose Joint Injection Code by Size For joint injection -- also known as arthrocentesis -- you select codes based on the joint size. For a knee injection, choose 20610 (Arthrocentesis, aspiration and/or injection; major joint or bursa [e.g., shoulder, hip, knee joint, subacromial bursa]). Difference: When the FP administers knee joint injections, she should indicate whether she performs the procedure on the right, left, or both knees. You'll include documentation with the claim, as needed, and append the appropriate modifier to 20610: Tip: Check for Correct Modifier Reimbursement The Medicare Physician Fee Schedule indicates that a 150 percent payment adjustment applies to procedure codes with a bilateral indicator of "1" (such as code 20610) when you submit the claim with modifier 50. "If you've been using modifier 50, look at your payments to see if the insurer has been paying you unilaterally (at 100 percent) instead of bilaterally (at 150 percent)," advises Joanne Schade-Boyce, RDH, MS, CPC, ACS, PCS, vice president of FairCode Associates LLC in Germantown, Md. Audits frequently reveal documentation and coding that supports a bilateral procedure that the insurer has paid unilaterally. The insurer might incorrectly process Medicare's preferred method of a one-line entry with modifier 50 (such as 20610-50). Private payers might want bilateral procedures on either two lines, with modifier 50 on the second line (20610, 20610-50), or no modifier with two units on a single line item (20610 x 2). Determine Whether E/M Applies Some office visits for knee injections qualify for an E/M code, but others don't. If the patient comes to your office specifically for a scheduled injection, you'll only report the injection code. If, however, the physician completes another service during the visit, an E/M code might apply. Example: The FP completes and documents an appropriate history and thorough examination of an established patient. He advises the patient to go through a series of knee injections, and the patient agrees. You can report an E/M code from 99212-99215 (Office or other outpatient visit for the evaluation and management of an established patient ...) in addition to 20610. Append modifier 25 (Significant, separately identifiable evaluation and management service by the same physician on the same day of the procedure or other service) to the E/M code.