The latest tracking poll from the Kaiser Family Foundation finds that, among uninsured adults, 43% don’t know when the deadline is or refused to answer. Five percent believe the deadline has already passed and 13% think it’s later this year.

The deadline for Americans without Medicare, Medicaid or job-sponsored insurance to sign up for a new private health plan through the Affordable Care Act’s federal or state exchanges is Monday, March 31. Those who remain uninsured after that date may be subject to federal fines and will be locked out of the individual private insurance market until open enrollment begins against in November. Those who experience a major life event, like a job loss or marriage, will be able to purchase insurance in the interim. (Expecting a surge in demand right before open enrollment closes, administration officials said Tuesday that Americans who begin the process of enrolling om coverage by March 31 will be able to complete the process after that date.) The fine for not having insurance in 2014 is $95 per person or 1% of income, whichever is greater. Those who meet certain criteria will be exempt, however.

The Kaiser poll, conducted March 11-17, also found that 50% of uninsured adults plan to remain without health coverage, despite the law’s new exchanges and federal subsidies to reduce the cost of premiums.