Debra is correct. Per CMS' NCCI Manual, Chapter 1:
"Each edit has a column one and column two HCPCS/CPT code. If a provider reports the two codes of an edit pair, the column two code is denied, and the column one code is eligible for payment. However, if it is clinically appropriate to utilize an NCCI-associated modifier, both the column one and column two codes are eligible for payment."
The "column two code" (formerly referred to as the "component code") needs the modifier to protect it, and it will not always have the lesser RVU value, for the same reason that CMS decided to stop calling it the "component code," which was:
"When the NCCI was first established and during its early years, the â€śColumn One/Column Two Correct Coding Edit Tableâ€ť was termed the â€śComprehensive/Component Edit Tableâ€ť. This latter terminology was a misnomer. Although the column two code is often a component of a more comprehensive column one code, this relationship is not true for many edits. In the latter type of edit the code pair edit simply represents two codes that should not be reported together."
If you were to bill two codes for which an edit exists together, and you put a Modifier 59 on the column one code, the column two code would still be denied, since that was the one subject to a denial and needing protection.
Seth Canterbury, CPC, ACS-EM