On Wednesday, Representative Kevin Brady, Republican of Texas and the chairman of the House Ways and Means Committee, acknowledged a long list of still-unresolved issues in the House’s draft bill, which is to be released Nov. 1. They included where to place the income limits for various tax brackets, whether to maintain or cut tax rates on top earners, and the fate of several critical components of the revamped corporate code.

Two issues in dispute flared up publicly: changes to retirement savings and to individuals’ ability to deduct their state and local taxes.

Mr. Brady seemed to defend a proposal to drastically lower the cap on tax-free retirement account contributions. He indicated that there were better ways to encourage the bulk of workers to save, even after Mr. Trump declared on Monday that “there will be NO change to your 401(k).”

“Right now, we are not a nation of savers,” Mr. Brady said at a breakfast convened by The Christian Science Monitor, adding: “We think in tax reform we can create incentives for Americans to save more and save sooner.”

Privately, though, a member of House leadership assured lobbyists on Wednesday that retirement account limits would not be touched in the draft bill.

House Republicans have been considering sharply reducing the amount that Americans are allowed to save, before taxes, in 401(k) retirement plans to $2,400 a year, from the current $18,000, or $24,000 for workers who are over 50. Lowering the cap would be unlikely to encourage more savings, research suggests, but it would amount to an accounting maneuver that would help Republicans make up some of the lost revenue from large cuts to business tax rates. Money in such retirement accounts is taxed when it is withdrawn. By taxing most deposits immediately, Republicans would push future tax revenue into the 10-year budget window they are now working in.