Question Modifier 90


Best answers
Can anyone provide Place of Service (POS) information on modifier 90, Reference (Outside) Laboratory.

Is this modifier applicable only to reporting for POS 11, Office, for the treating/reporting physician or other qualified health care professional that sends a lab out for testing?

Or can a facility apply this modifier for a lab they send out for testing?



Best answers
Below is the information I've been able to find on this.

40.1.1 - Claims Information and Claims Forms and Formats (Rev. 85, 02-06-04)
Claims for referred laboratory services may be made only by suppliers having specialty code 69, i.e., independent clinical laboratories. Claims for referred laboratory services made by other entities will be returned as unprocessable.

Independent laboratories shall use modifier 90 to identify all referred laboratory services. A claim for a referred laboratory service that does not contain the modifier 90 is returned as unprocessable if the claim can otherwise be identified as being for a referred service.

The name, address, and CLIA number of both the referring laboratory and the reference laboratory shall be reported on the claim

Modifier 90
Reference (Outside) Laboratory

Sometimes a clinical diagnostic independent lab, place of service (POS) 81, refers a specimen to another lab for testing, where a modifier 90 is appended.
Correct Use

  • Outside laboratory performs procedure, unrelated to treating/reporting physician
    • In most cases, lab furnishing the service would bill the claim
  • Possible for one lab to bill service performed by another lab
    • Referring = referring specimen to another laboratory for testing
    • Reference = lab that receives specimen from another lab and performs one or more tests on such specimen
  • Must append modifier 90 to referred laboratory test code
    • Item 20 mark "Yes" = outside lab
    • Purchase price must be reflected under charges
    • Complete item 32 with NPI, name and address where performed
  • Appropriate modifier 90 claims include two different Clinical Lab Improvement Amendment (CLIA) numbers
    • Reflect billing provider information
    • Laboratory where services were performed (reference lab)
  • Bill claims with modifier 90 and without modifier 90 separately
  • If no purchased services, leave item 20 blank
Inappropriate Use

  • Do not report modifier 90 with anatomic pathology and lab services
  • Do not append modifier 90 for drawing fee (36415)
    • Cannot be referenced out to another lab
Best answers
The POS designation identifies the location where the laboratory service was provided, except in the case of an Independent or a Reference Laboratory. An Independent or Reference Laboratory must show the place where the sample was taken (if drawn in an Independent Lab or a Reference Lab, POS 81 is reported; if drawn in a hospital inpatient setting, the appropriate inpatient POS is reported). All entities billing for laboratory services should append identifying modifiers(e.g., 90), when appropriate, in accordance with correct coding. For example: 1) If the physician bills for lab services performed in his/her office, the POS code for "Office" is reported 2) If an independent laboratory bills for a test on a sample drawn on an inpatient or outpatient of a hospital, it reports the code for the inpatient (POS code 21) or outpatient hospital (POS code 22), respectively. Hope this will help you.