Using multiple modifier -59 in laboratory testing, accurate use? Abuse?


Best answers
I am new to medical billing and coding ––duplicate CPT codes were encountered and appended modifier -59 to all codes relating laboratory services; would this be appreciate or misuse of modifier -59. All services related laboratory tests, however the test directory did have the same CPTs for many tests even though they were different distinctively different labs, employed different techniques, or varying values were obtained or reported. There are (4) diagnosis codes for the patient, should these be listed for each procedure, how should ICD-10 codes be references with multiple procedures?

Within this superbill, the only modifiers -59 used was written. Should any changes be recommended or made before saving the superbill or generating the statement?

  • Would any modifier adjustments be required?
  • Would modifier -91 be useful as replacement?
  • Am I abusing modifier -59 since it was the only modifier used?
Last edited:
I'll need a moment to write the list. Does it matter what labs were performed, given what was ordered by physician? The laboratory mapping from vendor Quest Diagnostic had duplicate CPTs with other different labs from vendor. How should we bill these with proper modifier? There were over 140 different tests which were ordered. All I have done was map the CPT codes and used the CPT description from the library.

I may work on a CPT procedure --> LAB FRIENDLY NAME in our coding software. When a test had the same CPT code, or at least 1 similar CPT code how should I reconcile this regardless?
Last edited:
Hi Trexxm :)
You do know lab codes are in panels right? Also bill with modifier 91 for duplicate lab test by same provider on same date. Sometimes a inpatient will be treated same day with 2 differ medical specialists (OB/GYN vs Gastro as example) treating pt...both running labs which may be duplicated. Each provider will request on lab order what test want for patient and give dx related to lab test he or she wants results on. I d code the labs per the provider who ordered them and reason why. As example CPT 84153 is prostate lab test so we use dx N42.9 sinc provider is searching for this future problem. Whereas pt. lacking Vitamin B lab use CPT 82607 then doc is wanting this to link E53.8 dx . But it depends on reason why provider is ordering the lab test...he or she should tell you on order with treating dx for the day treated. We get lab orders for doc wants to check on if pt abusing alcohol F10 or psych drugs F19, but results is negative then we use dx Z01.89 to link to CPT 84600 lab test
Well hope this data helps you. Also at our site our EMR system has an audit check when code labs are used.
Lady T🏷️(y)
Lab Test
Occult Fecal Test 82270 87177 87045 Possible Dx codes R15, K92, K59.89 K29.60 Z12.11

PAP 88035 88141 88143 Possible Dx code R87.62 D28.9 Z01.411, Z01.419

Pregnancy Test urine/blood 81025 Possible Dx codes 026.9 Z34.90 Z32.01 Z36.9

PSA Prostate 84153 Possible Dx N52, N40 N42.9 E29.1

Testosterone 84402 Possible Dx N46, N51 N52.9 Z31 Z20
Hi Trexxm
This lab list may help but doc should give you reason why ordering.
Thyroid 84484 Possible Dx E07.89 E21 R94.6

Vitamin B 82307 or Vitamin B 12 82607 Dx code E53.8

Vitamin D 82306 possible Dx code E55.9 D51.0
Lady T