Martha Luque has diabetes, so she knew she needed health insurance.

But the 60-year-old apartment manager almost lost coverage this year, because of the shifting landscape of California health programs.

Last year, Luque was one of 654,000 residents statewide enrolled in the Low Income Health Program, a pre-Obamacare initiative to try to cover those without insurance.

But, on Jan. 1, that program ended and the Affordable Care Act took over. Most of the former Health Program enrollees now qualify for Medi-Cal, the state’s version of Medicaid, which has been expanded to cover more of the nation’s poor.

But 24,000 of them do not.

Although they were notified that the program was ending and given information on Covered California, the state’s health-care marketplace, they have essentially been dumped from their health plan and left to fend for themselves on the exchange.

“They’re falling through the cracks,” said Dee Pupa, manager of the Health Program in Ventura County. “Health-care reform is very complex — I understand it because I live it everyday, but the typical person in the community, they don’t understand.”

No one knows how many of the 24,000 — all of whom had health benefits last year — are now going without, because state officials are not tracking those numbers.

“We do not have that information,” said Roy Kennedy, spokesman for Covered California. “We don’t have a way to track whether or not people who were in the (Health) Program are in Covered California.”

Although the insurance the low-income residents could sign up for via Covered California would be more comprehensive than what they received last year, it would also, in many cases, be more expensive, despite help from subsidies.

“I am concerned,” said Jake David, a family physician at Ventura County Medical Center, who sees many low-income patients. “A lot of the patients that were in ACE (Access Coverage and Enrollment, Ventura County’s version of the Health Program) and qualify for the exchange aren’t savvy enough or patient enough to work through that system to get covered. Those of them that are, there are still costs and I wonder if that is a prohibition.

“I have had patients who formerly had ACE arrive and not have any coverage yet. And I’m sure that there are patients who haven’t come back to see me because they don’t have insurance.”

In Ventura County, which was among the first of 53 counties in the state to implement the Health Program, administrators “had hoped that about half” of the 3,166 former enrollees who didn’t qualify for Medi-Cal would have signed up for Covered California, Pupa said. “But I really, really don’t know what that percentage is. That is my hope.”

Last week Pupa converted her Health Program intake office into a Covered California enrollment center. But only a handful of people showed up, she said.

The Health Program was not technically insurance, but it provided enrollees with affordable access to a network of doctors, clinics and hospitals in their counties. It was available to adults whose family incomes fell at or below 133 percent of the federal poverty level. In some counties, such as Ventura County, the program was open to those whose incomes were at or below 200 percent of the federal poverty level.

It is the enrollees in the higher income brackets who have been left to find insurance on their own.

Luque has diabetes, so she knew she needed to figure out how to maintain access to health care.

“It was difficult and it did take awhile,” she said of the three weeks she spent trying to figure out how to get insurance through Covered California. “I had two days to the deadline when I finally got through. I kept thinking what if I didn’t have all this time to spend on the phone doing this?”

At the 11th hour, Luque found out that she qualified for a subsidy and decided on a plan for $132 per month, with $40 co-payments for doctor’s appointments.

But even with the subsidy, it’s far more than she was paying last year. In the Health Program, she paid a $150 fee for the entire year and $10 for each doctor’s appointment.

Luque said she’s thankful she can afford her new premium, because she relies on health coverage.

“My medical bills aren’t really that big normally — it’s just going every three months making sure my blood levels are where they should be — but you just never know,” she said. “I was in a car accident in September and having ACE helped me a lot with my doctor’s appointments and stuff. I don’t care how much money you have in savings, it’ll take it if you don’t have insurance.”

David said he’s concerned about his former Health Plan patients who may now decide to risk going without insurance — or who simply don’t realize they’ve lost it.

“I think there were a lot of people that didn’t understand what their options were,” he said. “Even in late December, I was explaining it to patients.”

People have until March 31 to enroll for insurance this year via Covered California. If they miss that deadline, the next open enrollment isn’t until October, and their coverage wouldn’t begin until 2015.

“The nice thing about the ACE program was that we could enroll people at any time,” David said. “Frequently patients would come into the hospital for unforeseen reasons, and that day we could sign them up. Now it may be much more difficult to get people the services they need.”