For plans that comply with the Affordable Care Act, influenza or flu shots are one of the recommended preventive services that insurers must cover without cost-sharing as long as the shot is provided by an in-network provider. Whether the insurer has to cover the office visit, however, depends on whether there was a medical reason other than prevention for your doctor’s visit. So, if your flu shot wasn’t part of your annual physical, the office visit is not a preventive service, and you may be subject to cost-sharing. (45 C.F.R § 147.130(a)(2)).
On Private Health Insurance Coverage & The Health Insurance Marketplace