Polypectomy billed with colonoscopy as 45378 & 45385?

I'm looking at a bill for a polypectomy, tentatively billed with both

45378 (diagnostic colonoscopy)
and
45385 (polypectomy)

I understand that Medicare doesn't permit this, treating 45378 in the polypectomy as included, is that correct?

Would the either/or apply in all cases where CPT codes are used, or only when submitted to Medicare?