Wiki BASE CODE DENIALS

Within the past couple of months we have been receiving denials from various payers for missing "base code". Our base codes are on our claims. For example: 17000 x1 17003 x1 - two AK's removed. These are billed with an E/M -25 (with separate medical conditions addressed). We call the payer and they inform us of this denial, they pull the claim and confirm the base code is listed and send back. Sometimes the claim is paid and sometimes it is denied again - "missing base code". We submit an appeal. The appeal is denied, informing us the base code is missing. We are mostly noticing this with Blue Shield, Health Net and UHC. Some of them inform us to add the 51 modifier to the add-on code. I have been a coder for quite some time. None of this is making sense to me. Is this a glitch within a software or has something new been implemented?

Konda
What was the diagnosis code you billed with and was lesion removed it in the same body area? Also in documentation did provider mention body location ? For helpful tips see dx blocks of D17, L85.0 .At my past job always told add complimenting L98.9 and Z dx code last related to patient s condition or past history . Possible ending Z dx codes....Z12.83 or Z87.2 or Z85.828.
I hope this helped you Konda
Lady T