In its October 25, 2024, comments to CMS on recent gapfill pricing for molecular diagnostics, the Association for Molecular Pathology raised some concerns about transparency of pricing at MolDx under its proprietary (and non-public) Equitable Pricing Model (EPM).
https://amp.org/AMP/assets/File/advocacy/AMPComments-MACFINALGAPFILLdeterminationsFINAL.pdf?pass=12
While the internal rules are not known, the recent final gapfill prices show that in some cases, EPM results in a crosswalk to a CLFS fee schedule price, and in other case, it results in a de novo MolDx price.
You can find some of the pricing examples either in the public record or by searching the MolDx public database, DEX. DEX lists all services for which there are Z codes (over 15,000). In the test is coded by a CLFS CPT code, with a CLFS price, the DEX directory says "see CPT code" (it doesn't tell you which it is). If the test is coded with an unlisted code (81479) the DEX directory lists the price.
Paraffin versus Liquid Biopsy - $2916, $3649
For example, you can find examples in DEX of differential pricing of paraffin (FFPE) and liquid biopsy testing. The CARIS ASSURE test is MolDx-priced at $3649. This is a circulating tumor DNA test for single nucleotide variants and indels. (See a press release from 2022 here.) On the other hand, DEX lists the Caris CGP (comprehensive genomic profiling test) at $2916, which is a locally assigned code and price (81479 other molecualr test) that also matches the price of 81455 (CPT code for tumors, >50 genes). While the two tests are not identical, you can see the bonus for LBx methods (about +$740).
Minimal Residual Disease: Exome versus Periodic Test - $3878, $794
One common approach to minimal residual disease testing is an exome test followed by a bespoke (custom) patient test for recurrence of cancer. Invitae (now part of LabCorp) got codes for the exome (0306U) and each subsequent test (0307U). MolDx priced these by gapfill a year or two ago, at $3878 for the exome test and $794 for the recurring bespoke test. Since these codes are specific codes found on a fee schedule, MolDx DEX would just refer readers to "see fee schedule" to find the prices (leaving it to the reader to puzzle out that the coding is 0306U, 0307U). But the two prices provide relatively recent benchmarks on how MolDx values the up-front exome test versus the serial single tests.
Your Results May Vary -
If you were submitting similar tests for MolDx pricing today, you wouldn't necessarily get the same prices. However, examples like the above do give some approximate benchmarks for planning purpose.
Dizzyingly Complex
The examples above are pretty simple comparisons. If you get into some areas like MolDx coding for minimal residual disease testing, you'll need either a master's degree or three years of experience to figure it out. A teaching example I've used, there are well over 20 codes in the online DEX for Natera-related tests, including many variants for its MRD testing, with various prices.
