Units disagree
What does "units" mean on a medical bill, and why does mine not match?
Most medical bills have a units column. It says how many of a thing you got: how many hours of infusion, how many millilitres of a drug, how many days in a bed, how many 15-minute blocks of therapy.
When the bill says four and your Explanation of Benefits says one, the service is real and only the quantity is wrong — which makes it easy to miss, because nothing about the line looks out of place.
Why it is worth checking
Units multiply. A unit error on a $60 line is $180. A unit error on a drug billed per milligram can be thousands, and drug units are the ones most often wrong, because the billing unit and the dose are frequently not the same number.
What to compare
Put the bill and the EOB side by side and match on the procedure code and date of service, then compare the units column on each. Your plan adjudicated a specific quantity. If the bill charges for more, the extra was either never submitted or was reduced by the plan.
A reduction is informative on its own: it means the plan looked at the quantity and disagreed with it.
What to ask
Please send me the documentation showing [N] units of [service] were provided, and please correct the line to [what the plan processed] if you cannot produce it.
The documentation exists. For a drug it is the administration record; for time-based services it is the start and stop times in the notes. Asking for it is a normal request, not an accusation.
The ones worth double-checking
- Drugs billed by weight or volume. The unit on the claim form is defined by the code, not by the vial. A drug billed per 10 mg when 10 mg was given should be one unit, not ten.
- Time-based therapy and counselling. These are usually billed in blocks, and the number of blocks should match the documented minutes.
- Anaesthesia. Billed in time units with a base value added. A long procedure produces a large number legitimately, so compare against the operative report rather than against instinct.
- Room and board. Count the nights, not the days. A three-night stay is three units even though you were there on four calendar dates.
That last one catches people out constantly and is worth checking first, because it is the easiest to verify from memory.
This is general information, not legal, medical or financial advice, and not a statement about your particular bill. A difference between two documents often has an ordinary explanation, and the billing office is the one who can give it.