States Should Structure Insurance Exchanges to Minimize Adverse Selection

By Sarah Lueck
Center on Budget and Policy Priorities
August 17, 2010

The health reform law (the Affordable Care Act) relies primarily on states to establish health insurance exchanges — marketplaces that provide affordable, good-quality coverage options to individuals and small businesses. But it gives states substantial flexibility in how they structure the exchanges.

Adverse selection — the separation of healthier and less-healthy people into different insurance arrangements — will occur if a disproportionate number of people who are in poorer health and have high health expenses enroll in coverage through the insurance exchanges, while healthier, lower-cost people disproportionately enroll in plans offered through the individual and small-business markets outside the exchanges. If that occurs, the cost of exchange coverage will be higher than the cost of plans offered in outside markets. That would drive up costs not only for consumers and small firms purchasing coverage through the exchanges, but also for the federal government, which must provide premium subsidies to enable low- and moderate-income people to afford coverage in the exchanges.

Higher premiums would depress participation in the exchanges by individuals and small businesses, particularly by those people and firms that can obtain better deals in outside markets. That, in turn, could raise premiums even higher in the exchanges and could ultimately result in their failure over time.

Risk Adjustment and Risk Pooling Will Reduce But Not Prevent Adverse Selection

The law also requires use of a risk-adjustment system, in which plans with sicker-than-average overall enrollments receive payments to compensate them for their resulting higher costs. The payments would come from plans that enroll healthier-than-average people that do not cost as much to cover.

As CBO has warned, the inability of current risk-adjustment systems to fully adjust for differences in health care costs between low- and high-cost groups means that, among plans in the same risk-adjustment system, “premiums for enrollees in plans that attract higher-cost beneficiaries [could] rise substantially over time.”

Another potentially helpful provision of the Affordable Care Act requires a “single risk pool,” meaning that each insurer operating inside and outside of an exchange will be required to treat all of its enrollees as a single group when setting premiums.

These pooling requirements, however, have significant limitations — for example, the risk-pooling requirement would apply only to insurers that choose to sell products both inside and outside an exchange. And as noted below, even in cases when insurers do sell products in both markets, it is likely to be difficult to enforce the requirement and ensure that risk is actually being pooled. In addition, the requirement that insurers offering identical plans in both markets charge the same premium in both places is weakened by the fact that the Affordable Care Act does not require insurers participating in both markets to offer the same plans inside and outside the exchange.

Some Elements of the Affordable Care Act Leave Exchanges at Risk for Adverse Selection

Under the Affordable Care Act, the existing individual and small-group markets can continue to operate outside the exchanges. Many of the law’s requirements relating to individual and small-group insurance plans will apply regardless of whether the plans are offered inside or outside the exchanges. For example, all new plans offered — whether through the exchanges or through outside markets — will have to provide a package of “essential benefits” and a minimum level of coverage (as measured by actuarial value). In addition, the law’s new “rating rules,” including those that prevent insurers from charging different prices based on a person’s health status, will apply to new individual-market and small-group plans regardless of whether the plans are offered inside or outside the exchanges.

But various other Affordable Care Act requirements apply only to health plans offered through an exchange, such as requirements related to the adequacy of provider networks, reporting on health care quality, grievance procedures, marketing practices, and benefit design. In addition, the law allows the Secretary of the U.S. Department of Health and Human Services to set additional standards for plans offered through the exchange, which plans sold outside an exchange are not required by federal law to meet.

This leaves substantial opportunity for adverse selection because insurers in these external markets will effectively be competing for enrollees against the exchange plans, but will not have to comply with standards that are as strict. Insurers operating outside the exchanges could seek to take advantage of these looser rules to attract healthier people and businesses, while leaving sicker people to enroll in coverage through the exchanges. As a result, the differences in rules would likely create an unlevel playing field and thereby increase the likelihood of adverse selection against the exchanges unless states institute protective measures.

In addition, under the Affordable Care Act, states have the option of setting up two separate exchanges — one for individuals and another for small businesses. States that do so may find that the exchanges lack the necessary volume to attract a sufficient number of insurers, ensure a large enough pool of enrollees that is well-balanced between the healthy and the sick, and achieve the economies of scale that can keep an exchange’s administrative costs low.

(This paper focuses on the risk of adverse selection between a health insurance exchange and outside health insurance markets. Another type of adverse selection could occur among plans within an exchange; this will be the subject of a future analysis.)


By Don McCanne, MD

Any health care financing system that divides health care funds into separate risk pools inevitably experiences adverse selection. In fact, private insurers do all that they can to see that their own risk pools contain low-cost healthier individuals while shifting higher-cost individuals into other public or private risk pools. As this article indicates, numerous regulations can be introduced that may reduce the magnitude of these differences, but they can never be eliminated.

When Medicare was financed using a single risk pool, adverse selection did not exist. Once private insurers were allowed to offer options to the traditional Medicare program (Medicare + Choice and then Medicare Advantage), multiple risk pools were established providing an opening for private insurers to game the system – and game it they did. They skirted the rules to selectively market the healthier sector of the Medicare population. They further pushed up their overpayments by upcoding the diagnoses – creating the deception that their enrollees were sicker than they actually were so that they wouldn’t be subject to risk adjustment (adjusting payments to reflect the health status of those in the pool).

Who suffers? Individuals, employers, taxpayers, health care providers. Who benefits? The private insurers.

Adverse selection was not simply an inconvenient policy problem that the legislators had to fiddle with merely because they rejected the concept of a single universal risk pool that eliminates the problem of adverse selection. Far worse, it was a deliberate policy decision supported by the leadership of the private insurance industry who held the hands of the legislators as they led them down the primrose path to the everlasting bonfire that they call reform.

The Center on Budget and Policy Priorities (CBPP) report lists a few policy tweaks that are an attempt to patch some of the loopholes, but there are two major problems with their recommendations.

First, since the insurance exchanges are established on a state by state basis, each and every state must have its own enlightened and caring leadership that would oversee the intensive oversight efforts that will be required to reduce (but not eliminate) these injustices. That will never happen in most states.

The greater problem with the CBPP analysis and recommendations is that they completely excluded any consideration of the solution that really would work – a single universal risk pool through a single payer national health program, such as an improved Medicare for all.

This article is reprinted with permission from