# modifier 91 - have a question



## caniford (Dec 17, 2007)

I have a question about modifier 91 when i code 81001 and 81003 would I use the -91 on 81003?


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## thompsonsyl (Dec 17, 2007)

Hi,

According to a Medical Newswire article on use of Modifier 91 - 


*Answer:* When providers perform repetitive laboratory tests on the same day, append modifier -91 (Repeat clinical diagnostic laboratory test) to the test code. This lets the payer know that the tests you are billing are not duplicates. The instructional notes in CPT caution that you should not use this modifier to bill for tests that must be repeated because of testing problems with specimens or equipment. Also, you should not use it for codes that by definition require serial measurements. For instance, the code for glucose tolerance tests includes a number of measurements the physician must perform over a three-hour period. Modifier -91 is not intended to allow you to unbundle those tests and bill each one separately. 
*May 12, 2003, 11:50*

Also, since according to CCI Edits, 81003 is considered a component of 81001, I would think that it would also require an additional modifier to allow them to be billed together.

Hope this helps!


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