A subsidized state health insurance program that offers affordable coverage to people pre-existing health conditions hit the 5,000-member mark by its first anniversary, far below full enrollment.

California has $761 million in federal money to run the program until it ends in 2014. Initial projections showed the money could support average annual enrollment of 25,000.

The program has enrolled 228 members in the Sacramento region.

It’s unclear why the numbers are so low. The feds have lowered premiums twice in a program that started out with substantially lower rates than the state’s longtime Managed Risk Medical Insurance Program.

The new Pre-Existing Condition Insurance Plan is considered a bridge to 2014, when federal health reform will prohibit insurance companies from denying insurance to adults with pre-existing conditions or charging them more for coverage.

To be eligible, individuals must be lawfully present in the United States, have had no credible insurance coverage for the preceding six months and have a pre-existing condition shown by a denial of coverage, offered at rates he or she can’t afford — or a letter from a licensed health care provider.