Cold laser therapy would be reported using 97039 (Unlisted modality (specify type and time if constant attendance)). As per the code descriptor, document the time of performance. The service can be reported in multiple units where sufficient time is documented. Many carriers challenge services reported using an unlisted code such as 97039, and may deny payment on the basis that laser therapy is experimental/investigational. Such a determination permits you to bill the patient directly, and lowers the risk that the carrier will demand a future refund on the basis that the service was misrepresented using 97026 (Application of a modality to 1 or more areas; infrared). If the carrier has adopted HCPCS Level II private payer S codes into its code set, you would instead report cold laser therapy requiring constant attendance using S8948 (Application of a modality (requiring constant provider attendance) to one or more areas; low-level laser; each 15 minutes).