Pathology/Lab Coding Alert

Question: Our pathologist received a request for a consultation on slides from an outside lab. The submission included breast tissue and lymph node slides from a mastectomy dated March 16, 2008 and slides from a lung biopsy dated May 12, 2011. The patient is a Medicare beneficiary. I know that CMS has an MUE of one for 88321, but can we use a modifier and report 88321 x 2?

Illinois Subscriber

Answer: For a Medicare beneficiary, you should report only 88321 (Consultation and report on referred slides prepared elsewhere) for this case. You should not list multiple units of the code, even though the referral involved two accessions from two different surgical sessions.

You are correct that CMS has a limit of one unit of 88321 in its Medically Unlikely Edits (MUEs). Further, you're correct that you can override the MUE limits by using a modifier, in some cases.

Why only one 88321? Medicare has more than an MUE limit for 88321. CMS has a policy statement for this code, and you must follow the policy. As of Oct. 1, 2007, CMS limits you to billing only one unit of 88321 for the same patient on the same day, regardless of the number of specimens or separate outside cases that your pathologist examines.

The Correct Coding Initiative (CCI) policy manual states, "CMS payment policy allows only one unit of service for CPT® codes 88321, 88323, and 88325 per beneficiary per provider on a single date of service. Providers should not report these codes  on separate lines of a claim utilizing CPT® modifiers to bypass the MUEs for these codes."

Notice that Medicare's unit-of-service restriction also applies to these codes:

• 88323 -- Consultation and report on referred material requiring preparation of slides
• 88325 -- Consultation, comprehensive, with review of records and specimens, with report on referred material.

Other payers are different: You can bill multiple units of 88321 for some payers. The unit of service for "outside" consultations such as 88321 is not the specimen. CPT® Assistant, Dec. 2002 states, "[The] unit of service for codes 88321-88325 is considered the surgical pathology case or cytopathology case, which can include multiple specimens for review."

The "case" often links to the "accession" from the referring lab. So a case typically includes all tissue or cytology specimen(s) taken during a single operative session. Having different dates of service is a clear indicator that you're dealing with separate cases. In your question, you have two separate cases (accessions, dates of service), meaning that you can report 88321 x 2 based on AMA guidelines. Many payers accept billing in this manner, but some payers follow Medicare rules, so check before you bill.