Medicare Advantage Premiums Fall While Benefits Shrink: KFF Spotlight Exposes the Actuarial Trade-Off

KFF's 2026 Medicare Advantage Spotlight records average monthly premiums falling from $16.40 to $14.00 alongside supplemental benefit reductions across nearly every non-core category. The two moves happened together, in the same bids.

The number that connects them is the rebate. Premium buy-down and supplemental benefits are funded from the same pool, so a smaller pool forces a choice between them.

Key Takeaways

• $16.40 to $14.00 in average monthly premium against over-the-counter allowances offered by 66% of plans rather than 73%, meals by 57% rather than 65%, and transportation by 24% rather than 30%.
• Medical deductibles rose 72%, from $33 to $57, and the share of MA-PD enrollees facing a Part D deductible went from 23% in 2024 to 83% in 2026.
• Over 7% decline in Milliman's total value added, the largest single-year drop in that tool's history, split roughly $17 PMPM of Part C value and $4 PMPM of Part D.
• 75% to 65% is what a Star Rating drop from 4.5 to 3.5 does to a plan's rebate percentage, which is the mechanism behind Humana's benefit design for 2026.
• 4% to 33% enrollment losses at carriers whose value added declined, against 22% growth at one carrier that improved it.

What the Spotlight Records

The premium line moved a little and the benefit lines moved a lot, which is visible directly in the filings.

Over-the-counter allowances went from 73% of plans to 66%, meal benefits from 65% to 57%, transportation from 30% to 24%, and remote access technologies from 53% to 48%. Vision, dental and hearing stayed near-universal at 98% or above, but annual dental allowances and vision maximums thinned inside those categories rather than disappearing from them.

Zero-premium MA-PD plans fell by 231, a 9.5% reduction. That matters more for shopping behavior than the premium average does, because the zero-premium count is what makes MA visibly cheaper than traditional Medicare plus a supplement at the point of comparison.

The arithmetic for an individual enrollee runs the other way from the headline. Someone who used a $75 monthly OTC allowance in 2025 and lost it in 2026 saves $2.40 a month on premium and gives up $75 of benefit value, a net $72.60 monthly increase. The premium decline is real and small; the benefit reduction is larger in enrollee spending terms.

The Rebate Is Zero-Sum and It Shrank

The bid is where the two lines meet. A plan bidding below its county benchmark receives a rebate set by Star Rating, 50% of the difference below 3.5 stars, 65% at 3.5 stars and 75% at 4.0 or above, and must divide that rebate across premium buy-down, supplemental benefits and Part D cost reduction.

Run it. A 4-star plan bidding $50 under benchmark has $37.50 PMPM of rebate to allocate. Narrow the spread to $35 under the same rating and the pool is $26.25 PMPM, an 11-plus dollar reduction with no change in the plan's own cost structure. The actuary then chooses between a higher premium with the benefit package intact and a held premium with the package cut. The filings show which way most went.

Star Ratings move the same lever without any change in the bid at all. Humana's largest contract, covering roughly 45% of its enrollment, dropped from 4.5 to 3.5 stars between rating years, taking the rebate percentage from 75% to 65% on that book before any benchmark question arises.

Milliman's MACVAT analysis sizes what came out: over 7% off total value added, about $17 PMPM of Part C value and $4 PMPM of Part D, with average medical maximum out-of-pocket rising from $5,100 to $5,440 and medical deductibles from $33 to $57. Milliman also found carriers whose value added declined lost 4% to 33% of enrollment while one that improved its position grew 22%, which is the empirical anchor on how far the cut can go before it costs more than it saves.

What the Deductible Expansion Does to the Residual Pool

The Part D deductible move is the one with consequences past the bid year, because it changes who stays.

Going from 23% of enrollees facing a Part D deductible to 83% in two years introduces first-dollar cost sharing across most of the book at once. The near-term utilization effect is well established: first-fill delays, higher abandonment, more generic substitution. The reserving consequence is that completion factors calibrated on a benefit design without a deductible will understate early-period pharmacy claims, and the IRA's catastrophic layer redesign shifts high-cost claims onto plans in the same period.

The selection consequence is larger. Cost sharing falls hardest on members who use little care, because they pay the deductible and receive nothing back through the supplemental benefits that were cut. Those are the members whose retention holds a plan's risk pool together, and they are the ones for whom traditional Medicare with a supplement now compares better. Total MA enrollment is projected at 34 million for 2026 against 34.9 million in 2025, with MA share of Medicare slipping from 50% to about 48%.

Roughly 2.9 million enrollees were also forced to switch after carrier county exits, against a historical rate below 2%, and the plans absorbing them were operating under the same compressed economics that caused the exits. Nor does the rebate pool recover on its own: CMS proposed excluding unlinked chart review diagnoses from risk scores in the CY 2027 Advance Notice, an estimated $7.12 billion, which MedPAC supported. The 2027 bid begins from a smaller pool than the one that produced these cuts.