Accidents are the leading cause of death among young adults. You need to build layers of financial protection from the expenses of medical and health care over your lifetime for two reasons: 
1.    You may need it sooner than later. Neither when nor how much it will cost are predictable at any age.
2.    If you don’t start now inflation will only make it more difficult to catch up later. That’s why you and your employer pay into the Medicare Trust Fund from your first paycheck to your last.  
Medical insurance coverage is a basic requirement for avoiding significant medical debt. But basic medical insurance doesn’t cover most people’s healthcare costs entirely. There can be some large holes.

Medical policies require people to pay a portion of the cost in addition to premiums. Typically, they have deductibles (the initial amount), co-insurance (a % of the amount), and copays (Flat dollar amount) which means that medical expenses are shared, between the insured and the insurance company. Plans also have different networks of medical organizations. HMOs and EPOs are usually simpler to use and less expensive but have restricted and often geographically limited networks. PPOs and POS plans are at the other end of the spectrum with more extensive networks, but they can be more expensive and complex to use. 

Also, basic medical coverage doesn’t include lost income when you can’t work. It generally excludes gym membership, fitness trackers or fitness equipment to stay healthy. Medical services such as eye care, dental and orthodontic services, or hearing assistance are not covered, or covered separately.