Question: Recently my claims to Medicare are being denied when I submit a secondary diagnosis code. I’ve heard that this is happening in several states including Washington, California, and New York. Has there been a recent change in what secondary diagnosis codes are allowed? 

Answer: Medicare requirements for secondary diagnosis coding does differ from many other payers so it is essential to know and follow their rules. According to the most recent edition (August 2020) of the Medicare Benefit Policy Manual, Chapter 15, Section 240.12 (emphasis added), “The primary diagnosis must be subluxation, including the level of subluxation, either so stated or identified by a term descriptive of subluxation. Such terms may refer either to the condition of the spinal joint involved or to the direction of position assumed by the particular bone named.”

Since that doesn’t mention anything about the secondary diagnosis, the guidance we have from the Medicare Administrative Contractors (MACs) can provide further information about a secondary diagnosis. A review of current MAC Articles reveals that some of them include a statement about including other diagnoses such as:

  • “In addition to reporting the ICD-10-CM code for the level of subluxation, report any other pertinent ICD-10-CM codes.” (First Coast, A58412; Novitas A58345)
  • “...The neuromusculoskeletal condition necessitating the treatment must be listed as the secondary diagnosis.” (WPS Medicare, A56273)

Interestingly, articles from other MACs (e.g., CGS Administrators, Palmetto, Noridian) don’t say anything about other diagnoses. However, the Noridian website states (emphasis added): “Secondary diagnosis required to support condition causing primary diagnosis.” We interpret this statement to mean that a secondary, supporting diagnosis related to the subluxation must also be included on the claim.

Since Noridian is the MAC for your state of Washington (and many other states, including California and New York), as long as your claims were submitted in accordance with those guidelines and your secondary diagnosis was NOT a subluxation code, but rather supported your primary diagnosis as indicated in the following example of an entry on Item Number 21 on the 1500 Claim Form, you should be paid according to their rules:

21. Diagnosis or Nature of Illness or Injury

A.  S13.121A     B. G44.1      C. S13.4XXA     D. V43.51XD

However, it is known that some states have been experiencing a problem even when they do everything right. According to a statement from the Alaska Chiropractic Association, there was a problem with Noridian’s claims processing system and in several states, claims with a secondary diagnosis were being inappropriately denied even when they had an appropriate secondary diagnosis. In a situation such as this, be sure to check with your MAC if you have outstanding claims that still have not been re-processed.