If we perform most of the components of an obstetric panel in our hospital lab but we have to send out one component to a reference lab, would we append the modifier 90 to the entire panel, or do we have to report each component separately and append the modifier 90 to only the CPT® code that was sent out?


Modifier 90 does not apply to hospital claims for laboratory testing. The hospital laboratory will report the appropriate CPT code without modifier 90 appended.

The modifier is reserved for use on claims submitted by the independent laboratory that refers a specimen to another laboratory. There is no need to unbundle the CPT code for the obstetric panel for the purpose of appending the 90 modifier.

Apply the billing guidelines as applicable to the hospital laboratory setting, which would use the CMS-1450 institutional form. The physician laboratory or independent laboratory bills on the CMS-1500 professional format.

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Fee schedules, relative value units, conversion factors and/or related components are not assigned by the AMA, are not part of CPT, and the AMA is not recommending their use. The AMA does not directly or indirectly practice medicine or dispense medical services. The AMA assumes no liability for data contained or not contained herein.

CPT is a registered trademark of the American Medical Association.