In simple words: Modifier BL is used when a hospital outpatient setting purchases blood or blood products from a community blood bank, or charges for blood it collects in its own blood bank.

Modifier BL is appended to HCPCS codes when a provider, operating under the Outpatient Prospective Payment System (OPPS), purchases blood or blood products from an external source like a community blood bank, or when the provider's own blood bank assesses a charge for the collected products.

Example 1: A hospital outpatient department purchases units of packed red blood cells from a community blood bank for a patient requiring a transfusion. The HCPCS code for packed red blood cells would be appended with modifier BL., A hospital with its own blood bank collects and processes whole blood, which is later separated into components. When these components, like platelets or fresh frozen plasma, are used for a patient, the provider appends modifier BL to the corresponding HCPCS code., An outpatient surgical center purchases blood products from an external blood bank. Modifier BL is appended to the HCPCS code when billing for these blood products under OPPS.

Documentation should include the date of service, number of units, appropriate HCPCS code for the blood product, and modifier BL. Separate documentation for processing and storage services should also be maintained, if applicable.

** When billing only for blood processing, do not use revenue code 038X, modifier BL, or blood-related value codes, and do not apply the Medicare blood deductible.