Coding Basics:
Choose the Right Modifier for Repeat or Bundled Tests
Published on Sat Jan 01, 2005
-59 or -91 tells the whole story If your lab performs the same test twice or performs two tests that yield similar results, payers typically don't want to cover both services. But if you know when to append modifiers -59 and -91, you could win deserved pay for your pathologist's work.
Sometimes physicians find it medically necessary to carry out repeat or bundled tests, and that's when you'll need to know about modifiers -91 (Repeat clinical diagnostic laboratory test) and -59 (Distinct procedural service) to get paid for your work, says Elizabeth Sheppard, HT (ASCP), manager of anatomic pathology at Wake Forest University Baptist Medical Center in Winston Salem, N.C. Use -91 for Repeat Clinical Lab Tests If your lab repeats the same clinical diagnostic test because the physician requires sequential results for medical purposes, you should report the second and each subsequent code with modifier -91.
Example: The physician orders a potassium test three times during the day to monitor the patient's response to potassium replacement therapy. "Report 84132 (Potassium; serum) for the first test, and 84132-91 for each of the subsequent tests," Sheppard says.
You should also use -91 if the lab performs a panel of tests, and then performs one component of the panel later in the day for medically necessary reasons.
Case in point: The lab performs a renal function panel (80069, Renal function panel), and the physician orders a follow-up blood gas for carbon dioxide later in the day. "You should report the subsequent blood gas as 82374-91 (Carbon dioxide [bicarbonate])," says Kenneth Wolfgang, MT (ASCP), CPC, CPC-H, CEO of Chargemaster Maintenance Services, a laboratory consultation company in Portland, Ore.
Watch out: Don't report modifier -91 if the lab repeats a test due to testing problems or to confirm initial results. "Payers don't cover these types of quality-assurance reasons for repeating a test," Sheppard says.
Sometimes a more specific code describes a series of repeat lab tests. In those cases, you should always report the more specific code, not multiple units of the repeated test code with modifier -91. For instance, report a glucose tolerance test as 82951 (Glucose; tolerance test [GTT], three specimens [includes glucose]), not as three units of 82947 (Glucose; qualitative, blood [except reagent strip]) with modifier -91. Report -59 for Bundled Services When two services provide similar diagnostic information, payers say that the codes are "bundled," and they won't pay for both tests for the same patient on the same day. "Code bundles include tests that are a component of a more comprehensive test, or tests that have different methods [...]
