According to a blog by Diana Richard on the XIFIN website, dated April 7, United Healthcare (UHC) will require Medicare Advantage claims to include Z-codes, effective June 1, 2021. Read it at XIFIN - here.
There have been news stories about UHC requiring various types of registry codes for lab tests dating back to mid-2020 (see a subscription story at Dark Report here.)
This is the first major sale of DEX Z-codes to a commercial payer that I've read about, although it appears to apply only to United's Medicare Advantage contracts and not its overall book of business as a payer. According to Kaiser, Medicare Advantage has 24M enrollees in 2020, about 40% of Medicare. According to United, they have 6.5M Medicare Advantage patients in 2020. That gives United about 27% of the MA beneficiaries (or about 10% of all Medicare benes, including the FFS ones.)
Palmetto GBA (which is related via holding companies to South Carolina BCBS) took over the DEX or Z-Code assets last summer, as was announced at the time when the DEX website was rebranded. (Here, here). There are currently about ~14,000 entries in the online DEX test library - here. Some locally-set prices (prices that are not on a national fee schedule) are newly available in DEX (here).
The Z-code system was originated by McKesson circa 2010, prior to the modernization of the CPT genomic coding system. It was spun off independent of McKesson as Change Healthcare, which in turn is now owned by United, but along the way the Z-code business silo was acquired by Palmetto. In March 2021, AHA opposed the union of Change and United/Optum in a filing with the Department of Justice (here).