SACRAMENTO . (AP) — California’s health insurance exchange is still sluggish when it comes to resolving customer service problems, leaving many people unable to access health care or finalize their tax returns, a consumer advocacy group said Thursday.

Covered California has been slow to fix enrollment mistakes entered into its computer system, according to the Health Consumer Alliance, which is made up of legal aid groups throughout the state.

Exchange staff has a limited ability to update a state computer program for determining whether people are eligible to enroll in Covered California or in Medi-Cal, the state’s low-income health program, the group says.

Covered California’s executive director, Peter Lee, responded Thursday at the board meeting that “a very small percentage” of customers file appeals when they are rejected, and the exchange is committed to resolving problems quickly. Since March, the agency says it has added staff to try to resolve disputes informally without having to go through an administrative law proceeding.

“We still have work to do,” Lee said.

The agency will provide a detailed report on the number of appeals and their status at the next board meeting in October, he said.

The alliance also claims Covered California has failed to correct tax subsidy forms in a timely manner, preventing people from getting tax credits or amending their taxes. For example, advocates said a woman from the Inland Empire has not been able to correct her tax subsidy form since Jan. 28.

“We are concerned that public support for the (Affordable Care Act) will erode as more and more consumers encounter these types of tax problems and face exposure to IRS debts and penalties,” the group wrote in a letter to exchange board members this week.

Covered California said it is looking to troubleshoot information technology problems so staff can make changes directly rather than having to file help desk tickets that can take weeks to resolve. Accenture won a $359 million contract in 2012 to build and maintain the state’s online platform for health insurance programs called the California Healthcare Eligibility, Enrollment, and Retention System, or CalHEERS.

“The challenges with big IT, it does not necessarily mean nimble IT,” Lee said. “We’re working to speed those up. But the issue of having effective and as prompt as possible resolution to appeals is something we take very seriously.”

Jen Flory of the Western Center on Law and Poverty, a member of the alliance, said she was pleased to hear the exchange set a goal of mid-September to resolve tax forms but worried two years remains too long for some CalHEERS system fixes.

“We do want to work with staff to get some timelines to make sure these people that are waiting to get into plans actually have access to care,” Flory said.

Earlier this year, Covered California apologized for sending out about 100,000 incorrect tax forms to people who received sliding-scale subsidies to help them purchase private health insurance.

The exchange acknowledged sending inaccurate coverage information on 1095-A forms when 800,000 forms went out for the first time this year. The federal health care law requires most people to have insurance or face a tax penalty that increases each year.

The penalty for a person who makes $40,000 a year will increase from $299 in 2014 to nearly $600 this year. And a family of four with that same income would see fines increase from $500 to nearly $1,000.