If you put the rendering NP's info, it wouldn't be billing "incident to".
Per Medicare:
Billing
Services rendered 'incident to' a physician's service should be billed under the employing physician's NPI, or in the case of a physician directed clinic the supervising physician's NPI, and are reimbursed as if the physician performed the service (no modifier required). If the physician is non-participating, then the services can be billed as either assigned or non-assigned.
Services rendered 'incident to' a nonphysician practitioner's service should be billed under the employing practitioner's NPI, or in the case of a physician directed clinic the supervising practitioner's NPI, and are reimbursed as if the practitioner performed the service.
The following practitioners must accept assignment: PAs, NPs, CNSs, CP, CSWs, CRNAs, CNMs and Registered Dieticians. Since these practitioners must accept assignment, any services billed 'incident to' these practitioner must be billed as assigned.
Incident to billing is paid at 100% of the physician fee schedule, whereas the qualified practitioners billing under their own billing numbers are paid at 85% of the physician fee schedule. If service delivery does not meet all incident to criteria, but qualifies for billing by the practitioner, payment is made at 85% of physician fee schedule when billed by nonphysician practitioners or 100% of fee schedule when billed by therapists.