The average monthly premium for a Medicare Advantage plan will be $3.98 in South Carolina in 2027, $4.08 in Mississippi and $4.24 in Missouri, the Centers for Medicare & Medicaid Services (CMS) says in its state fact sheets. All three are well below this year’s averages of $9.39, $11.18 and $8.19. Open enrollment begins October 15. A lower average does not mean every plan costs less, and premiums are only part of what members pay.
The question for people on Medicare Advantage in these states is whether a cheaper-looking plan stays cheaper once their own prescriptions and doctors are counted. Open Enrollment runs from October 15 to December 7, and any change made in it takes effect January 1, 2027. A plan with a $0 premium can still carry a deductible, copayments for specialists and a drug tier that prices a regular medicine high, none of which show up in the monthly figure.
A $3.98 average premium says nothing about what one plan charges for one person’s prescriptions. The 2027 Medicare Open Enrollment Decision Kit includes a cost calculator spreadsheet that compares plans on cost, drugs and doctors, plus the Open Enrollment calendar for the October 15 to December 7 window.
Three states, three lower averages
South Carolina’s CMS fact sheet puts the average monthly Advantage premium at $3.98 for 2027, down $5.41 from $9.39. The state has 1,285,904 people with Medicare and 97 Advantage plans, two more than the 95 offered in 2026. CMS says 100 percent of people with Medicare there will have access to an Advantage plan with a $0 monthly premium.
Mississippi shows the largest dollar drop of the three, $7.10, from $11.18 to $4.08. The state has 657,224 people with Medicare, and its plan count rises from 93 to 102. Becker’s Payer, which tallied the fact sheets, lists Mississippi among the largest premium decreases in the country this cycle, alongside Minnesota.
Missouri’s average falls $3.95, from $8.19 to $4.24, with 1,371,496 people on Medicare and plans growing from 157 to 174. Mississippi, Missouri and South Carolina all report a $0-premium Advantage option available to every person with Medicare in the state. In each state, the fact sheets show more plans on offer, not fewer. Each state also lists stand-alone Part D drug plans for people who keep Original Medicare: 8 in South Carolina and 9 apiece in Mississippi and Missouri, with the lowest stand-alone premium at $5.30 a month.
What a state average leaves out
The figure is an average across the plans sold in a state, and a plan with no premium pulls it down. The fact sheets do not break the averages out by plan or insurer, and CMS has not published a reason for the drop in these states. A reader looking at $3.98 or $4.24 is seeing the middle of a spread, with some plans at $0 and others well above the average.
The same fact sheets show how different the averages are from state to state. Wyoming’s rises to $69.23 and Minnesota’s falls to $59.40, so a monthly premium of a few dollars is a pattern in some states, not a national rule. The national average CMS projects in its September 28 announcement is $12.00 for 2027, down from $14.37.
That announcement also says roughly eight in 10 Advantage members can stay in their current plan with the same or a lower premium. The other two in 10 face a higher premium or a plan that is no longer offered, and for that group a state average says the least.
Total cost on a drug list
Most of what separates one Advantage plan from another shows up only after a prescription list and a doctor list are entered. Two plans with nearly the same premium can price the same medicine differently, and a doctor missing from a network turns a covered visit into a full bill. For a person on several regular drugs, a $4 premium difference can be small next to a drug-tier difference over twelve months.
The cheaper averages also come with more choices, which makes the sorting longer. Missouri adds 17 plans, Mississippi adds nine and South Carolina adds two, according to the fact sheets. More plans mean more drug lists and networks to test. The fact sheets also show how many people in these states lean on help with drug costs: 35.24 percent of stand-alone drug plan members in Mississippi, 21.99 percent in South Carolina and 21.16 percent in Missouri receive Extra Help, the federal program that lowers drug plan costs for people with limited income.
Comparing total cost in Plan Finder before December 7
Medicare’s free Plan Finder on Medicare.gov prices each plan in a ZIP code against the drugs, doses and pharmacy a person enters. It shows the plan’s estimated total cost for the year, not just the premium, and lets the results be sorted by that total. Running the current plan through the same tool shows what staying put would cost in 2027.
Before starting, gather each prescription with its dose, the names of doctors and hospitals to keep, and the pharmacy used. Check any plan that looks cheap for its drug deductible, for whether each regular medicine is covered, and for whether each doctor is in the network. A difference in any of those can outweigh the few dollars a month that the state averages highlight.
CMS’s fact sheets give the monthly figures, $3.98, $4.08 and $4.24, and the date that decides when they matter: December 7, 2026. Anything chosen by then takes effect January 1, and the premium is the first number on a plan’s page, not the last one.
A $4 premium is not a $4 plan
The mistake that costs money is choosing the lowest premium without pricing the drugs, because a cheap monthly figure can sit on top of a higher drug deductible. The 2027 Medicare Open Enrollment Decision Kit runs plans through a cost calculator spreadsheet that compares plans on cost, drugs and doctors and adds the Open Enrollment calendar so the December 7 close does not pass. The kit is 55 pages.
Put the Open Enrollment calendar and cost calculator to work before December 7 →
This article was prepared with AI assistance from cited public sources and reviewed before publication.
