Laboratory Question for the Week of May 22, 2023


When is modifier 33 reported?


In response to the Patient Protection and Affordable Care Act (PPACA), modifier 33 was released by the AMA and became effective for billings with the date of service of January 1, 2011. So how is this modifier different from previous modifiers? Modifier 33 communicates to a payer that the service or test being billed is preventive under pertinent laws and indicates that patient cost-sharing is not applicable. Be warned though that for separately reported services that are specifically identified as preventive, the modifier should not be used. Even more, the Medicare Preventive Service Benefit manual does not reference this modifier as applicable for laboratory testing billed to the Medicare program. Understand that at present, the application of this specific modifier for billing of laboratory services should be restricted to the intentional instruction of commercial and private payers.


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