The group rallied on the Capitol steps and is meeting with lawmakers as part of Reproductive Health and Rights Lobby Day 2012, organized by Planned Parenthood and NARAL Pro-Choice Washington.
The "Parity Act" would require health plans that cover maternity care to provide equal coverage for abortion, after health care reform is implemented.
Most plans in Washington already cover abortion, but supporters of the measure say they worry administrative burdens of health care reform could cause some to stop covering abortion services.
Sen. Steve Hobbs, sponsor of the act in the Senate, spoke at the group's rally on the Capitol steps.
"We're not changing anything really," Hobbs said about the measure, after addressing the crowd. He said he expects it to have the votes to pass out of committee in the Senate.
The House version of the proposal passed a committee vote last week, and could see a floor decision.
Opponents of the measure say that it would limit options for businesses with objections to plans that offer abortion coverage. It would exempt religiously sponsored plans and one multi-state plan that would not cover abortion.
UPDATE - 6:38 P.M.
The bill passed out of the Senate Committee on Health and Long-Term Care , and now awaits a floor vote.
