When the definition says "bilateral," it means "bilateral." Don't append modifier -50 (Bilateral procedure) to two different procedures unless performed on identical anatomic sites on opposite sides of the body.
Use modifier -50 for bilateral bone marrow biopsies or aspirations if the sites are, in fact, bilateral not just separate sites and the physician performed the exact procedure on both sides.
You should report the biopsy code, 38221, with modifier -50, says Carolyn M. Davis, CCP, CCS-P, the billing supervisor for Oncology Hematology West in Papillion, Neb. You have two technically bilateral sites (modifier -50) that each involved a bundled biopsy and aspiration procedure, 38221.
Watch our for payer preferences when you report bilateral procedures. Some payers require that you report these procedures with site modifiers -LT and -RT, the HCPCS alpha-modifiers, says Marcella Bucknam, CPC, CCS-P, CPC-H, HIM program coordinator at Clarkson College in Omaha, Neb. Some payers may request that you instead use modifier -59 on both the biopsy and aspiration codes to report services done on bilateral sites, she says. Ask your payer how it recognizes bilateral procedures.