Democrats are on the cusp of making the most significant changes to Medicare in more than a decade, which would bring lower drug prices and out-of-pocket costs for some of the program's 64 million enrollees.

Why it matters: New limits on how much patients will have to pay for medicines annually could offer a lifeline to seniors with conditions like cancer or multiple sclerosis who face thousands of dollars in drug bills, and lower overall prices would provide relief to even more enrollees.

The big picture: Nearly 1.5 million would benefit from a $2,000 cap on out-of-pocket spending in Medicare's Part D drug benefit, and 1.3 million from the elimination of a requirement they pay 5% of total drug costs if they exceed a catastrophic coverage threshold, the Kaiser Family Foundation estimates, based on 2020 data.

Yes, but: While the bill is projected to save taxpayers hundreds of billions of dollars over the next decade, opponents of the bill argue these savings won't be felt by patients.

At least some of the policies could provide a tonic to seniors on fixed incomes who've been rattled by soaring prices and economic anxiety.

From 2024 to 2029, the Democrats' plan would limit premium growth in the Part D program to 6%.

The other side: The pharmaceutical industry argues such negotiations would quash innovation and cut off venture capital funding for promising cures.

The bottom line: The Democrats' plan caps years of futile efforts to change the drug pricing equation and, despite its limitations, lets Medicare for the first time use its purchasing power.