AmeriHealth New Jersey lost money, but how much?

Cooper Health System, which owns 20 percent of AmeriHealth New Jersey,  said its share of the health insurer's 2016 loss was $5.29 million, down sharply from a $9.26 million loss the year before.

Based on Cooper's 20 percent stake, that would translate into overall AmeriHealth New Jersey losses of $26.43 million last year and $46.28 million the year before, but the New Jersey insurer's majority owner, Independence Health Group, disputed the magnitude of the losses.

"We don't have any insight into Cooper's accounting or any adjustments that they might apply to the share of the results as reported by us. At this time, we would decline to provide a specific number on the [AmeriHealth New Jersey] losses," Independence said in an email.

Cooper stood by its filing: "Cooper's financial filings are accurate as related to its AmeriHealth investment. We cannot speak to AmeriHealth's finances," Cooper said in an email.

Cooper paid $8.5 million for its 20 percent interest in AmeriHealth New Jersey in 2014 as part of a plan to jointly offer insurance plans in South Jersey. Cooper made additional capital contributions of $5 million in 2015.

Patricia Dorris Crenny, an accounting instructor at Villanova University, said a possible explanation for the discrepancy would be that Cooper is adding in an accounting expense of some sort, but that is not evident from Cooper's financial statement.

Independence, whose main subsidiary in Southeastern Pennsylvania is Independence Blue Cross, has struggled with out-of-network costs in New Jersey, chief executive Daniel J. Hilferty said in a March interview on the company's 2016 financial results. New Jersey regulations allow consumers to use out-of-network providers for certain services, such as pediatrics and autism, Hilferty said.

AmeriHealth New Jersey, which had about 70,000 consumer members last fall, dropped its Medicare Advantage plans for 2017, citing "increased utilization and inadequate funding" as the biggest reasons.

Overall, Independence had a profit of $67 million last year, up from a $54.4 million loss in 2015.