A fund to help cover health insurance for more than 5 million early retirees will stop taking claims for expenses incurred after Dec. 31, according to a notice in the Federal Register. Set up under health care reform, the fund is used to reimburse employers who subsidize health insurance for early retirees, ages 55 to 64, not yet eligible for Medicare. The Early Retiree Reinsurance Program fund started with $5 billion, and was intended to last through 2013. However, by Dec. 9, about $4.5 billion had been spent. The fund was exhausted because of heavy enrollment by firms and unions that tapped into the money to help provide insurance to early retirees.