Part of CPT and HCPCS coding are modifiers. Modifiers are two digit codes that indicate a modification to clarification to the CPT or
HCPCS. Modifiers can be found in the CPT and HCPCS books in Appendix A. In many
instances the proper use of a modifier can avoid claim denials. Understanding
modifiers is very important.
There are three kinds of modifiers and understanding the
differences is imperative as it directly relates to their usage. The first are
evaluation and management (E&M) modifiers, these can only be used on
E&M services. Remember that E&M are office visits only, these do not
include diagnostic testing or surgery, please review the evaluation and
management section in CPT coding earlier in this writing.
The second type is procedure modifiers. These modifiers only
apply to procedures including diagnostic and therapeutic and surgery. Included in
this group are location modifiers, such as RT for right and LT for left. Finally
the last group is general modifiers that may be used on either type of service.
On the CMS 1500 form, modifiers are listed in the service
line just after the service code, like this: (this sample uses the modifier 25
next to 99213. Please note, a modifier 25 generally indicates the presence of
another CPT code on the same claim. This is not depicted in the image because
this image is strictly to show you the location of the modifier fields.)
As you can see, there are 4 modifier spots. On a paper claim
form, you can only have 4 modifiers. It is pretty rare to need more than 4
modifiers per claim line or service line.
Follow this link to see a complete list of modifiers and
their descriptions from Medicare: Modifiers for Billing
