If courts ultimately rule that Obamacare’s requirement that individuals buy health insurance is unconstitutional, there would be virtually no impact on the health insurance markets as long as the rest of the law remains standing.

That’s the assessment of people on both sides of the debate over the Affordable Care Act. Severing the individual mandate from the law and leaving the rest of Obamacare to stand is one possible outcome of the legal battle, although certainly not the only one, analysts and legal observers say.

Another possibility would be for the appeals court to rule that the individual mandate is...