JPMorgan Chase & Co. is unrolling a $20 billion, five-year investment across its businesses based on benefits from recent tax-law changes, a softer regulatory environment and its overall growth.

The largest U.S. bank by assets is planning to open up to 400 branches in new markets across the country, grow its home lending to lower-income consumers and boost wages for some retail-banking employees, among other changes, Chief Executive James Dimon said in an interview.

JPMorgan is one of many large companies passing its employees or clients some of the windfall of billions of dollars in expected additional profit from the tax-code overhaul enacted late last year. The bank’s effective tax rate will be about 19% this year and 20% over the near term, down from 35% previously, finance chief Marianne Lake said during an earnings call earlier in January.

Mr. Dimon said during the same call that the bank could have roughly $3.6 billion in additional net income in 2018 as a result of the tax overhaul.

JPMorgan took a one-time, $2.4 billion charge in the fourth quarter due to the tax changes. But Ms. Lake and Chief Executive James Dimon spoke at length about future benefits and hinted at some changes the bank was planning.