Friday, March 17, 2023

AI Exploration Series: ChatGPT 4 Advises Labs How to Maximize the Crosswalk/Gapfill Price of a New Test

For ChatGPT 4:

Medicare sets prices for all the services it pays for.  It pays for laboratory test services by CPT code.  When their is a new CPT code, for a new test, Medicare must assign a price.   The method is provided at 42 CFR 414.508.   

If there is a comparable test which is already priced, Medicare assigns that price to the new test and new code (this is called "crosswalking.")  If there is no comparable test, Medicare assigns the price with an ad hoc method called "gapfilling."  In "gapfilling," Medicare policymakers consider 4 factors.  These are (1) what the lab charges and what it discounts, (2) the resources required to perform the test, (3) the payment amounts of othe payors, and (4) the payment amounts and resources needed for similar tests.   (Note, regarding point 4, that there is however no test so similar that it could have been used as a crosswalk). 

You are an expert policy consultant, and your client has a new genetic test.  It wants to get the highest possible price assigned.  What approach should the lab use?


As an expert policy consultant, I would recommend the following approach for your client, the laboratory, to obtain the highest possible price assigned for their new genetic test:

  1. Prepare a strong case: Gather and organize detailed information on the four factors that Medicare considers in the gapfilling process. Develop a clear, concise, and well-organized case that supports your desired price.
  2. Lab charges and discounts: Document the lab's charges for the new test, focusing on emphasizing its uniqueness, complexity, and the value it adds to patient care. Ensure that any discounts provided are justified and do not undermine the perceived value of the test.
  3. Resources required: Clearly outline the resources required to perform the test, such as personnel, equipment, reagents, and quality control measures. Emphasize any unique or specialized resources that may justify a higher price.
  4. Payment amounts of other payors: Research and compile data on payment amounts from other payors, such as private insurance companies, for similar genetic tests. Highlight instances where these payors have reimbursed at higher rates, and use this data to support your proposed price.
  5. Payment amounts and resources for similar tests: While no test is so similar that it could be used as a crosswalk, analyze and document the payment amounts and resources required for tests that are relatively similar to the new genetic test. Highlight any additional resources, complexity, or benefits of the new test that could justify a higher price. 
  6. Collaborate with stakeholders: Engage with stakeholders, including healthcare providers, patient advocacy groups, and professional organizations, to gather support and endorsement for the new genetic test. This may help strengthen the case for a higher reimbursement rate. 
  7. Communicate effectively: Present your case clearly and effectively to Medicare policymakers, highlighting the unique value and benefits of the new genetic test. Be prepared to address any concerns or questions they may have and demonstrate why the proposed price is justified.

Remember, the ultimate decision lies with Medicare policymakers, and they may use their discretion to determine the appropriate price. 

However, by providing a well-researched and compelling case, you will increase the chances of obtaining the highest possible price for the new genetic test.

AI / Canva

My Comment:

That is a good answer.  But, I explained CMS might set the price by "crosswalk" to a comparable test, or if not that, to "gapfill" using the rules you discuss.  You did not really consider that the lab ought to strategize if crosswalk is a better option than gapfill.  Can you discuss?

AI: Second Answer

Apologies for the oversight. You are correct that the laboratory should strategize to determine whether pursuing a crosswalk or gapfill method would be more advantageous for obtaining the highest possible price for the new genetic test. Here's a discussion of both approaches:

  • If the lab can identify a test that is comparable to the new genetic test, but not so similar that it would automatically be used as a crosswalk, the lab could consider advocating for the crosswalk method. This could be a viable strategy if the comparable test has a high reimbursement rate that the lab believes would be beneficial for their new test. 
  •      In this case, the lab should:
  • Identify a comparable test with a high reimbursement rate: Research and analyze existing CPT codes and their associated prices. Find a test that is reasonably comparable in terms of complexity, resources required, and clinical utility.
  • Document similarities: Clearly outline the similarities between the new genetic test and the identified comparable test, emphasizing aspects that support the case for a higher reimbursement rate.
  • Advocate for the crosswalk method: Present a well-organized case to Medicare policymakers for using the crosswalk method, explaining why the chosen comparable test is a suitable reference for pricing the new genetic test.


If the lab believes that the gapfill method would result in a higher price for the new genetic test, they should pursue the gapfill strategy. As mentioned in my previous response, this would involve preparing a strong case based on the four factors considered by Medicare policymakers in the gapfill process.

Comparison and strategy:

To determine which method – crosswalk or gapfill – would be more advantageous, the lab should:

  • Assess potential crosswalk options: Evaluate the reimbursement rates of any potentially comparable tests and determine if the crosswalk method would yield a higher price than the gapfill method.
  • Analyze pros and cons: Weigh the pros and cons of each method, considering factors such as the strength of the case, the likelihood of success, and the potential impact on the lab's reputation and relationships with stakeholders.
  • Choose the most advantageous method: After careful analysis, choose the method that is most likely to result in the highest possible price for the new genetic test.
  • Prepare a robust case: Regardless of the chosen method, invest time and resources into building a solid case that demonstrates the value of the new genetic test and justifies the desired price.
By carefully evaluating both the crosswalk and gapfill methods and strategically choosing the most advantageous approach, the lab can increase its chances of securing the highest possible price for the new genetic test.