"President Obama has promised open deliberations in front of C-SPAN cameras for all Americans to learn how reform will impact them. However, a 1,500 page bill, full of carve-outs and backroom deals, is currently being brokered behind closed doors," Johanns said.
"We're about to significantly alter one-sixth of our economy-now is not the time to shut Americans out," He added.
Senate Democratic leaders met Thursday night with White House officials to consider including a government-funded public health insurance option, along with a provision allowing states to opt out of it, in a health care overhaul bill.
Two senior Democratic Senate sources told CNN Thursday that Senate Majority Leader Harry Reid is leaning toward a public option with the state opt-out provision in the Senate health care bill that will reach the full chamber in coming weeks.
Johanns also questioned the need for the health care legislation if costs remain so high that the majority of Americans can't afford it.
"True health care reform should decrease what you're paying, and make it easier for you to receive care," Johanns said.
"The bottom line is this: we're nearing 10 percent unemployment. We have a record budget deficit, and many families are working hard just to put food on the table and to pay the bills. Yet, there's no doubt about it: these proposals will negatively impact pocketbooks and paychecks across America," Johanns said.
Also on Thursday, thirty-six moderate House Democrats threatened to vote against the current health care bill the chamber's leaders are drafting because they don't believe it will sufficiently reduce long-term health care costs.
–CNN's Dana Bash and Deirdre Walsh contributed to this story.