Pathology/Lab Coding Alert

CPT® 2024:

Add to the Trove of Category III Slide Digitization Codes

Published on Fri Nov 10, 2023

Match 30 new add-on codes to the appropriate base procedure code.

Last year, CPT^® added 13 new Category III add-on codes for digitizing glass microscope slides for pathologic diagnosis. This year, year you’ll have an additional 30 new codes in CPT^® 2024, effective Jan. 1

Greet the Codes

The new codes for 2024 are in the range +0827T-+0856T. Each code includes the following components:

The initial phrase “Digitization of glass microscope slides for…;
A description of the procedure for which the slides are prepared;
The final phrase “List separately in addition to the code for primary procedure;” and
A note that instructs you to use the code “in conjunction with [the code number for the primary procedure].

Example: Here’s a new code for digitizing 88104 cytopathology slides: +0827T (Digitization of glass microscope slides for cytopathology, fluids, washings, or brushings, except cervical or vaginal; smears with interpretation (List separately in addition to code for primary procedure)

(Use 0827T in conjunction with 88104).

Taken together, the codes describe slide digitization paired with the following primary procedures:

Non-gyn cytopathology codes: 88104-88112 (+0827T- +0830T)
Cervical or vaginal cytopathology (Pap) codes: 88141 (+0831T) and 88160-88162 (+0832T-+0834T)
Fine needle aspiration (FNA) codes: 88172-88177 (+0835T-+0837T)
Referred material consultation codes: 88321-88325 (+0838T-0840T)
Intra-operative consultation codes: 88331-88334 (+0841T- +0844T)
Immunofluorescence stain codes: 88346, +88350 (+0845T, +0846T)
Archived specimen retrieval code 88363 (+0847T)
In situ hybridization stain codes 88364-88366 (+0848T- +0850T)
Morphometric analysis, in situ hybridization codes 88368, +88369, 88377 (+0851T-+0853T)
Peripheral blood smear code 85060 (+0854T)
Bone marrow smear code 85097 (+0855T)
Electron microscopy code 88348 (+0856T)

Follow the Guideline Updates

CPT^® 2023 provided an introduction to the slide digitization codes last year, and CPT^® 2024 updates the introduction to provide some clarification. These guidelines explain how you can — and can’t — use these codes. Study the following key takeaways from the intro section to make sure you’re using these codes correctly:

The purpose of the slide digitization is for pathologic diagnosis that is distinct from direct microscopic exam.
Don’t use these codes if the digitization is solely for the purpose of archiving, research, training, tumor boards, algorithm validation, etc.
The images may be used for pathologic diagnosis in real time or stored for later and/or off-site examination.
The slide digitization must produce whole-slide images. The Food and Drug Administration (FDA) approves certain systems for producing these slides, which are validated for pathology diagnosis (read more at https://www.cap.org/protocols-and-guidelines/cap-guidelines/current-cap-guidelines/validating-whole-slide-imaging-for-diagnostic-purposes-in-pathology)
Don’t use these codes for any other slide digitization system, such as using mobile phone or tablet to send still or video images of slides or portions of slides.
Report one of the digitization codes only with the paired primary-service code.
The unit of service is a one to one match with the primary pathology service.

Significance: Glass-slide digitization may allow use of artificial intelligence (AI) algorithms to aid interpretation and diagnosis of the slides. It may also expand the network of those who can view the slides to optimize diagnostic specialization and improve patient outcomes.

Don’t Abuse Add-On Status

When you see the “+” symbol in front of a code, as you do with each of the 30 new slide digitization codes, you know that you’re dealing with an add-on code.

Key: You should never list an add-on code without also listing a “primary” procedure code. “An add-on code describes additional work associated with a specific primary procedure or service,” reminds R.M. Stainton Jr., MD, president of Doctors’ Anatomic Pathology Services in Jonesboro, Arkansas.

In the case of these 30 new codes, each one describes additional work to digitize microscopic slides prepared for a specific cytopathology, surgical pathology, or ancillary procedure.

Grasp Why You Should Use Category III Codes

The Centers for Medicare & Medicaid Services (CMS) does not assign relative value units (RVUs) to Category III codes.

That means there is no established fee schedule for the codes. Individual payers will establish coverage and payment for these codes.

That lack of payment makes some coders want to skip using the codes. But that would be a mistake.

Key: Regardless of current pay, your lab should use these codes if you perform the described services. “Reporting the Category III codes provides the data for clinical usage that could impact conversion to a Category I code and future payment,” explains Terri Brame Joy, MBA, CPC, COC, CGSC, CPC-I, product manager, MRO, in Philadelphia.

Temporary: CPT^® lists “temporary” codes with four numerals followed by “T” in the Category III section. The purpose of these codes is to allow data collection regarding how often clinicians perform a particular service. That means you should not use an unlisted Category I code if CPT^® provides a Category III code for a procedure — the latter takes priority, according to the section guidelines (You can view the most current code list at www.ama-assn.org/practice-management/cpt/category-iii-codes).

Note: Category III codes have an expiration date, typically after five years. Before expiration, the AMA either converts the procedure to a Category I code or archives the code due to limited use.