First, one suggestion, if you're posting a question about Medicare, please specify which MAC you have since each MAC has their own LCD and coverage policies.
According to First Coast, 20611, 76492,77012,77021, 76881 and 76882 are non-covered services. Fluoroscopy may be covered if properly documented. Since I deal with both NGS JK and Palmetto I checked both of these LCD's to compare them with First Coast, neither of them list these codes as non-covered. However, LCD #s L29307 for FL and L29408 for PR and FCSO Coverage News items state "The local coverage determination (LCD) for viscosupplementation therapy for knee contains the following language related to the non-coverage of imaging procedures (e.g., 20611, 77012, 77021, 76881, 76882 or 76942).
Imaging procedures performed routinely for the purpose of visualization of the knee to provide guidance for needle placement will not be covered. Fluoroscopy may be medically necessary and allowed if documentation supports that the presentation of the patient’s affected knee on the day of the procedure makes needle insertion problematic. No other imaging modality for the purpose of needle guidance and placement will be covered.
Therefore, these services will be denied."
So it seems if you have First Coast then these codes will not be paid even with modifiers.