Medicare and others have been talking about special status for FDA Breakthrough Review devices (BT) for several years, with the Trump administration finalizing a major regulation in mid-January 2021. The Biden administration delayed the regulation on Mach 17, and issued further plans on May 18, including a delay until December 2021.
Expect some news in September 2021.
A new version of the rule is now being reviewed by the Office of Management and Budget (OMB) - link here, and update paragraph (8/27) here. This usually means that a Federal Register publication is due within a few weeks.
As proposed in January, the Medicare Coverage for Interim Technology or MCIT rule would have granted four years of automatic Medicare coverage to any BT device, effective for four years from the date of FDA approval. For links to the various stages of initial and interim rulemaking, see the OMB link above.
The tracking page also links to several official government and stakeholder meetings about the rule - here.