BOSTON — The co-chairs of a legislative committee reviewing the state’s new recreational marijuana law said Tuesday that when it comes to taxing sales of the drug lawmakers will look to strike a balance between raising revenue for the state and discouraging the underground market.

Democratic Rep. Mark Cusack, of Braintree, and Democratic Sen. Patricia Jehlen, of Somerville, were recently named to head the panel, which is expected to recommend legislation this year. During an interview on WBUR-FM, Cusack said it was important to find the “sweet spot” for taxing marijuana.

“We also want to make sure we are not overtaxing and sending people back to the black market,” he said.

The law, approved by voters in November, calls for a 3.75 percent excise tax on recreational pot sales that would be assessed on top of the state’s regular 6.25 percent sales tax. Cities and towns could assess an additional 2 percent tax on sales within their own communities.

Cusack and Jehlen noted that several states that previously legalized recreational marijuana, including Colorado, Washington and Oregon, impose significantly higher tax rates.

Marijuana stores are not expected to open in Massachusetts until mid-2018 at the earliest.

The lawmakers said they would seek a tax rate sufficient to generate revenue to cover regulatory and enforcement costs and low enough to prevent marijuana users from returning to illegal sources. The goal, Jehlen said, is to provide safe access to marijuana and “kill” the underground market.