Primary Care Coding Alert

Answer: Many coders wonder if they should report modifiers RT (Right side), LT (Left side), or 50 (Bilateral procedure) for bilateral X-rays. In fact, most insurance providers will accept either one code with modifier 50 attached for bilateral claims, or two separate codes with the LT and RT modifiers.

To indicate to which foot you are referring on a Medicare claim, you can only append modifiers LT and RT to X-rays, or if it’s a toe X-ray, one of the toe modifiers, such as T3 (Left foot, fourth digit). Some private carriers may require modifier 50, so you should always check with your payers to see what they prefer. With toes specifically, it’s likely best to append the T modifiers and not the RT and LT. Many payers are denying the LT/RT modifiers for toe services/procedures.

You should also avoid billing an X-ray with modifier 50 and two units of service. Coding this way is technically billing for four units — not for a right and left foot.

Remember: Never append modifiers LT or RT in conjunction with a toe modifier because the toe modifier already indicates which foot the toe is on.