If you happen to be reading this on Tuesday, Oct. 1, know that today is historic. I say that because open enrollment starts today as part of the Affordable Care Act (ACA) and will end March 31, 2014. Insurance coverage for those who obtain it during open enrollment can start as soon as Jan. 1, 2014. If we had been around in 1940, when the first Social Security checks were issued, or in 1965, when the first Medicare card was issued (it went to President Harry Truman) then we would have some idea of today’s significance.

You can tell your grandchildren you remember the “real” start of the ACA — the day the exchanges (also now called marketplace) started. Remember the idea behind the exchanges — it is that most of the 45 million Americans without health care coverage can obtain coverage either by qualifying for Medicaid or through purchasing insurance on the exchange. Insurers selling plans on exchanges will have to provide a set of essential benefits and many who get their insurance through an exchange will receive a subsidy based on their income. For example, a family of four with income between $23,550 and $31,400, will pay 2 percent of that income for coverage, while a family of four with income between $70,650 and $94,200, will pay 9.5 percent.

Here are two more examples from Texas: after subsidies, a 27-year-old with an income of $25,000 would pay $145 per month for the benchmark second-lowest-cost silver plan, $133 for the lowest-cost silver plan, and $83 for the lowest-cost bronze plan. A family of four with an income of $50,000, again, after subsidies, could expect to pay $282, $239 and $57, for the same plans.

And, it is the law that we (all of us) either have to have health care coverage or pay a fine.

How is this going to work out? That remains to be seen.