As it turns out, my health insurance plan is a Limited Indemnity plan, so apparently, there are certain healthcares services that they won't actually cover, such as diagnostic lab (blood work and the like) . . . which nobody explained to me when I was sold this plan in the first place almost two years ago.
However, my provider was able to enroll me in an additional plan - at no extra cost to me - that helps with discounts for a variety of healthcare services, including those that my current insurance won't cover, so that's nice.