The Highmark Health organization continues to be financially strong and viable despite growing competition and marketplace challenges. Operating revenue for the year ending December 31, 2015 was $17.7 billion, continuing the organization's steady consolidated financial growth of nearly $1 billion for two consecutive years. Highmark Health reported a deficit of revenue over expenses of $85 million, which is in line with the prior year. The organization had net investment earnings of $294 million in 2015, an increase of $40 million over the prior year, and a gain of $249 million associated with the merger of Blue Cross of Northeastern Pennsylvania (BCNEPA) into Highmark Inc.
Overall, our consolidated financial performance remained consistent year-over-year, which is notable when you factor in our conservative accounting approach to federal government reimbursements related to the Affordable Care Act (ACA) exchange products. Had we received those reimbursement funds, Highmark Health would have had positive net income in 2015.
Highmark Health's consolidated balance sheet continues to reflect a solid profile with net assets of $5.2 billion and $6.3 billion in cash and investments as of December 31, 2015.
This financial strength enabled us to invest nearly $500 million in 2015 in our core and growing businesses to improve health care quality and access for our health plan members as well as other health plan members on our platform.
The health plan business delivered mixed results in 2015, reporting a loss of $438 million, which includes a loss on the government business (Medicare, Medicaid and the ACA programs) of $655 million and a gain on the commercial business of $217 million. Approximately 90 percent of the government loss is attributable to the ACA business, which has been challenging because the population that the health plans are serving is utilizing significantly more services than we contemplated. For every dollar in premiums the health plans collected on this program in 2015, they paid $1.20 in claims.
The ACA losses are well above the prior year due to several factors, including higher enrollment in the products, increased utilization of services, and Highmark Health's decision (beginning at the end of 2014) to recognize only those funds actually received from the federal government. As a result, 2014 and 2015's combined losses total more than $500 million.
While the ACA products did not perform well, the health plans' commercial business continues to perform very well from both an enrollment and a financial perspective. Highmark health plans generated operating gains on the commercial business of $217 million in 2015 compared to $34 million reported in 2014. Members and customers continue to benefit from the health plans' comprehensive, competitive coverage options and provider networks.
People are choosing Highmark insurance plans and the organization continues to grow revenue from this business. Commercial membership remains strong with 95 percent member retention across all markets in 2016. This same 95 percent member retention was also seen in the Medicare Advantage segment. Total health plan enrollment as of December 31, 2015 stands at 5.2 million members; this includes more than 260,000 new BCNEPA members with the completion of the BCNEPA merger and continued diversification of enrollment with growth in Medicaid in Delaware and West Virginia.
Allegheny Health Network continues to make progress in its turnaround, recording an operating loss of $36 million, a slight improvement over the prior year. The performance improvement was driven by increased volumes at Allegheny Health Network with a 3.5 percent increase in inpatient volumes and 1.8 percent increase in outpatient registrations. These volume gains more than offset an increased depreciation expense of $17 million associated with the significant level of capital investment at Allegheny Health Network.
Our health plan members, and the Western Pennsylvania community at large, continue to choose Allegheny Health Network due to the extraordinary high quality of care it provides and we are very pleased with the continued development of its capabilities and services in the region.
During 2015, capital expenditures of nearly $180 million were made to fund expansion in key clinical areas as well as community-based facilities, including the health and wellness pavilion in Bethel Park, which began operations in July 2015 and the new state-of-the-art Allegheny General Hospital Critical Care and Telemetry Unit for Cardiovascular Patients, which opened in January 2016. All of these investments were supported by the addition of 152 new physicians to the network.
Highmark Health and Allegheny Health Network continued the implementation of the EPIC medical records platform, bringing a substantial number of physicians, Allegheny General Hospital and Forbes Hospital onto the system. The hospital system continues to realize operating efficiencies and continuous improvement in the already exceptional quality of care offered at Allegheny Health Network with the capabilities gained through an integrated state-of-the-art medical records platform.
Highmark Health's vision, dental and health risk solutions businesses maintained their strong performance throughout 2015, achieving combined earnings of $229 million.
HVHC Inc., our integrated vision solutions company, had a near record year, with revenue of more than $1.5 billion and an operating gain of $122 million. Visionworks, the retail subsidiary of HVHC, continued to expand its footprint, opening 56 new retail stores in 2015, bringing the current location total to more than 700. Davis Vision, the managed vision care subsidiary of HVHC, also continued to grow both the top line and the bottom line by adding more than 1.9 million lives to its insurance enrollment, putting it on track to provide coverage to more than 22 million members in 2016.
The health risk solutions business, HM Insurance Group, saw its most profitable year to date, delivering operating gains of $69 million, a nearly 70 percent improvement over the prior year. At the same time the company continued to grow through $189 million in new business sales of its stop loss, managed care reinsurance and workers' compensation insurance products during 2015.
United Concordia Dental, Highmark's dental solutions company, continued to focus on growth in 2015 while contributing $38 million in operating profits. United Concordia was successful in renewing two long-term federal contracts in 2015 and was awarded the five-year, $2.9 billion Tricare Dental Program contract, which is scheduled to begin in 2017.
HM Health Solutions, our technology-based solutions company that currently supports several Blue Cross Blue Shield plans in multiple states on state-of-the-art technology platforms, reported an operating gain of $7 million for the year.
Having completed the migration of Independence Blue Cross in 2015, HM Health Solutions is currently servicing 8.3 million members on the insurance platform, an increase of 2.2 million members or 36 percent since 2010. It is also in the process of migrating a second large Blue plan, Blue Cross Blue Shield of Minnesota, which will grow enrollment by an additional 2.1 million members by early 2017. Once the Minnesota business is on the insurance platform, HM Health Solutions will service as many non-Highmark members as it does Highmark members, enabling us to continue to invest in and develop the platform into a world class solution for plans that are unable to fund these investments on their own.