HR 1976, titled To establish an improved Medicare for All national health insurance program, was filed on March 17 and nearly identically succeeds HR 1384 from the previous session. Introduced by lead sponsor Rep. Pramila Jayapal (D-WA) with 112 original cosponsors, an additional two have already signed on. The full text, list of cosponsors, and other details about the bill are available at congress.gov here.
The 2019 Senate bill was introduced in April 2019 with 16 cosponsors by Sen. Bernie Sanders, who had introduced a nearly identical bill in the 2017 session. We expect him to submit a new bill soon. Details about the bill are available at congress.gov here.
Principal features of the two bills may be compared here.