The Supreme Court is not expected to rule until late June on the constitutionality of the individual mandate and the fate of the 2010 health care law, but no matter what decision is handed down, the affordability of health care coverage remains an unmet and enduring challenge.

Rising health care costs are the most significant barriers to access to health care coverage, for both families and those employers who offer health insurance to almost 157 million Americans.  From 2000 to 2011, average annual health insurance premiums more than doubled for employers, from $4,819 to $10,944, according to the Kaiser Family Foundation.

These steep increases have been partly driven by increases in state-mandated health care benefits. From 2000 to 2010, the growth in health insurance premiums has tracked with the growth in benefits, according to the Centers for Medicare and Medicaid Services. More than 2,150 individual health care benefit mandates have been enacted across the 50 states.

All employers are wrestling with these steadily increasing costs. For many, especially small businesses straining to survive in the struggling economy, the rising cost of health care has left them with no easy decisions about how to continue offering coverage to their workers. And some small-business owners have never been able to afford coverage in the first place.

This struggle to afford health care coverage will continue for employers regardless of the Supreme Court’s decision. But choices made by state and federal policymakers in implementing the overhaul’s “essential health benefits” requirements could make matters worse for small-group and individual health plans.

Under the law, the essential health care benefits package must include 10 general categories of services: ambulatory patient services; emergency services; hospitalization; maternity and newborn care; mental health and substance use disorder services including behavioral health treatment; prescription drugs; rehabilitative and habilitative services and devices; laboratory services; preventive and wellness services and chronic disease management; and pediatric services including oral and vision care.

Some recent proposals would increase coverage and make the package even less affordable.

Health and Human Services Secretary Kathleen Sebelius has indicated her intention to allow states to incorporate their existing benefit mandates into the package. In addition, some groups are advocating applying Medicare regulations on private-sector prescription drug coverage. These ideas create the potential for more benefit mandates or federal regulations on top of new categories of essential services, which will further raise costs for employers and individuals.

Employer-sponsored health plans already provide generous benefits. The National Association of Health Underwriters recently conducted a survey of more than 1,000 of its members who specialize in matching health coverage to employers.  The survey showed that services including emergency, physician and hospital care; in-patient rehabilitation; nursing facilities; hospice care; prenatal, delivery and infant care; and organ transplants were all already covered under nearly every employer-sponsored plan. This includes generous prescription drug coverage.

Indeed, current prescription drug coverage offered by small-group plans was found to be broader than the drug coverage HHS has said it intends to include in the essential benefits package, according to a January 2012 study by Avalere Health. The private sector is currently providing generous prescription drug coverage with minimal regulatory oversight, which permits greater competition and the prospect of more affordable coverage as a result.

Allowing or requiring states to add mandated benefits or public-sector rules to the essential health benefits package without giving strong consideration to the added cost will further undermine the affordability of health coverage.

The Institute of Medicine recognized the relationship between the scope of the essential health care benefits package and its cost when it cautioned last fall that “the EHB must be affordable for consumers, employers and taxpayers.”

Unless HHS and state lawmakers heed this wise advice, the essential health care benefits package will succeed only in making health care coverage more costly for small businesses and families.

Neil Trautwein is vice president and employee benefits policy counsel at the National Retail Federation and chairman of the Essential Health Benefits Coalition.