House Speaker Paul D. Ryan said Wednesday that his health-care proposal must change to pass the House, marking a significant retreat from his earlier position that the carefully crafted legislation would fail if substantially altered.

Ryan acknowledged that changes would be made two days after an analysis issued by the Congressional Budget Office prompted a fresh round of criticism of his proposal. Among the report’s projections was that 14 million fewer Americans would be insured after one year under the Republican plan.

Speaking after a private meeting of GOP lawmakers, Ryan said that leaders would “incorporate feedback” from the rank-and-file in response to the CBO findings. He did not repeat his previous comments calling support for the bill a “binary choice” for Republican lawmakers.

“Now that we have our score we can make some necessary improvements and refinements to the bill,” he said, referring to the CBO’s estimate of the effect on the number of those covered by health insurance and what the GOP proposal would cost.