Medicare Compliance & Reimbursement

Question: When we code for drug wastage, I'm always concerned we'll make an error. I have heard that there is an easy way to accurately calculate wastage. Can you shed any light on this?

Answer: The key to accurately calculating drug wastage begins with knowing which drugs are single-dose vials and when you should expect waste to occur.

There is a simple formula you can use that applies to all drugs from a single-dose vial:

Step 1: Add the dose given and the amount wasted to determine the total amount.

Step 2: Divide the total amount by the drug's billable unit to determine the quantity of units you should bill.

Example: The doctor administers 125 mg of oxaliplatin to the patient (J9263, Injection, oxaliplatin, 0.5 mg), using three 50-mg single-dose vials.

Here's how you'd calculate your drug wastage:

Step 1: 125 (mg given) + 25 (mg wasted) = 150 (total mg)

Step 2: 150 (total mg) divided by 0.5 mg (oxaliplatin's billable unit) = 300 (total units billed)

Experts note: According to the CMS Web site, if you use a single-dose vial on multiple patients, you should assign the remaining waste to the last patient on whom you use the single-dose vial.

Remember: When you only use the same vial on a single patient, you will also need to bill it entirely to that single patient. You should never report waste on multi-dose vials.