Government employees are guaranteed coverage throughout shutdowns, but new hires or those who recently made changes to their plan could find themselves caught in the bureaucratic slowdown.
And if the gridlock persists, unpaid federal workers could be billed directly for their share of health-care costs, which are normally subtracted from their paychecks.
If they can't afford those bills, their coverage could be terminated.
The National Association of Insurance Commissioners released a statement explaining that the shutdown could result in financial hardships for some people and encouraging insurance companies "to exercise judicious efforts to assist these policyholders and work with them to make sure that their insurance policy does not lapse."
The situation is more dire still for federal contractors, some of whom are receiving notice already that their health insurance has expired or will do so within the next few weeks. There were some 4.1 million government contractors in 2017, according to Paul Light, a professor of public service at New York University.
Andrew Leyder, a data analyst on contract at the Department of Transportation in Washington, D.C., received the bad news in an email from his boss this week, "After negotiating with CareFirst for weeks since this very painful government shutdown, we regret to announce that, due to lack of payment, our group health insurance was terminated on Thursday."