Given the premium increases that took effect in most areas for 2018, it’s essential for anyone who is eligible for premium tax credits – or who might be eligible with an income fluctuation later in the year – to enroll through the exchange if and when they have a special enrollment period. Don’t sign up for an off-exchange plan and miss out on the possibility of much more affordable premiums via a tax credit.
When a clearer distinction is intended, healthy is used to describe the state of the object, and healthful describes its ability to impart health to the recipient. Vegetables in good condition are both healthy (i.e., not rotten or diseased) and healthful (i.e., they improve the eaters' health, compared to eating junk food). By contrast, a poisonous plant can be healthy, but it is not healthful to eat it.