An independent analysis said taxpayers making more than $1 million would get hit with tax increases averaging $100,000 next year under House Speaker John Boehner's alternative tax bill.
The Tax Policy Center said some low-income people would get smaller tax increases because the plan would let expire several tax cuts first enacted as part of President Barack Obama's 2009 economic stimulus package.
Boehner's bill is scheduled for a vote by the House on Thursday, though Senate Democratic leaders say it has no chance to pass the Senate. The Ohio Republican offered it as a backup plan in case stalled talks with Obama fail.
If Congress and the White House don't reach an agreement, taxes would go up for nearly every American family as part of the year-end "fiscal cliff."
Higher Medicare premiums are probably in store for many seniors if there's a budget deal.
Both sides agree on expanding a current, little-known law so more retirees considered well-off by the government are required to pay higher premiums for outpatient and prescription coverage. That would raise $20 billion or more over 10 years.
But it could come as a shock to many seniors who consider themselves solidly middle-class, and by no means wealthy.
Right now about 5 percent of Medicare beneficiaries pay higher premiums. That number could grow to 25 percent if the change goes through.
The higher premiums kick in for individuals making more than $85,000 and couples earning above $170,000.
Watch 10TV and refresh 10TV.com for the latest news.