DOVER — Delaware officials have decided not to develop the state's own health insurance exchange under the Affordable Care Act and instead will keep the current federal partnership model. Delaware was granted approval in June to develop a state-based health insurance marketplace, but Health and Social Services Secretary Rita Landgraf told the Delaware Health Care Commission the state will not move forward with the plan. Landgraf informed federal officials of the decision in a Wednesday letter to Health and Human Services Secretary Sylvia Burwell. "As a state partnership marketplace, Delaware will continue to retain plan management and consumer outreach, assistance and education, as well as final Medicaid eligibility determinations," Landgraf wrote. "Delaware will continue to utilize the federal technological platforms for enrollment and data reporting, consumer outreach and education efforts, and finalization of qualified health plans." Delaware officials had considered a state-based exchange amid uncertainty about whether the U.S. Supreme Court would uphold government insurance subsidies for millions of people, including more than 85 percent of the roughly 24,000 Delawareans with active coverage under the health care law. The court's ruling upholding the subsidies in all states — not just those operating their own exchanges — was a major factor in deciding to keep Delaware's partnership model, Landgraf said. She also noted that Delaware would have faced uncertain costs to continue using the federal government's enrollment portal and would have had to pay for "navigators" who help people through the enrollment process. Currently, the federal government picks up the entire $600,000 tab for Delaware's navigators. A recent survey shows that the percentage of uninsured adults in Delaware declined from 14.3 percent in 2013 to 10.8 percent last year, with the most significant gains in the black population, according to state officials. But Landgraf said Thursday that more work needs to be done to reach the Hispanic community, especially in Sussex County. State officials said last month that the percentage of uninsured Hispanics grew from 37.1 percent in 2013 to 40.2 percent last year. Landgraf said she is working with members of a subcommittee of the Delaware Hispanic Commission to address the issue. Landgraf also noted that Delaware lagged behind national averages in enrolling adults aged 18 to 44 under the Affordable Care Act and the state had fewer enrollees in "silver" level insurance plans, despite the availability of government subsidies. The Obama administration has asked states to carefully scrutinize big rate increases sought by insurers providing coverage under the health law so that insurance can remain affordable for consumers. In Delaware, Highmark Blue Cross Blue Shield has filed for an average rate increase of 25.4 percent for 2016 ACA individual plans. The specific rate increase would vary by plan, ranging from 19.6 percent to 29.2 percent. Aetna Health Inc. and Aetna Life Insurance Co. are seeking to raise average premium rates for individual plans by more than 16 percent.