Summary and Key Takeaways: TL;DR

The 2026 Medicare Open Enrollment season in Sonoma County revealed distinct trends that diverge from national patterns. While Medicare Advantage gained popularity across the U.S., local beneficiaries overwhelmingly favored Medicare Supplement plans. This shift was driven by a strong demand for provider access, fewer network limitations, and more predictable costs.

• 87% of local enrollees chose Medicare Supplement plans over Advantage.
• Prescription drug coverage changes triggered most plan reviews.
• Plan exits and provider network shifts forced many to reconsider options.
• Access to doctors and hospitals outweighed the appeal of added benefits.
• Local data emphasized the growing need for annual Medicare plan reviews.
  

What Local Enrollment Data Reveals About Medicare Choices in Northern California

Medicare Open Enrollment is often discussed through national headlines and statewide enrollment totals. Those numbers are useful, but they rarely explain what Medicare beneficiaries experience at the local level. Sonoma County offers a clear example of why local data matters.

During the 2026 Medicare Open Enrollment period, Sackett & Associates Insurance Services conducted hundreds of one-on-one Medicare plan reviews with residents across Sonoma County. These reviews provide a grounded view of how people actually make Medicare decisions when faced with plan exits, prescription changes, and shifting provider networks.

To document these trends, Sackett & Associates published the 2026 Northern California Medicare Open Enrollment Annual Report. This blog highlights the key findings and explains what they mean for Medicare beneficiaries in Sonoma County.

Why Sonoma County Medicare Trends Look Different

Most Medicare research focuses on enrollment growth. It tracks how many people enroll in Medicare Advantage or how fast certain plans expand. That approach misses a critical factor: local healthcare structure.

Sonoma County is not dominated by a single integrated health system. Many residents rely on independent doctors, local specialists, and multiple hospital networks. When plans change networks or exit service areas, the impact is immediate and personal.

Because of this structure, Medicare choices in Sonoma County are often driven by access and continuity rather than by premiums or extra benefits.

Medicare Advantage vs Medicare Supplement in 2026

Nationally, Medicare Advantage enrollment now represents more than half of all Medicare beneficiaries. California follows that pattern in many counties, especially urban areas with managed care systems.

Sonoma County did not follow that trend in 2026.

Based on direct enrollment outcomes reviewed during Open Enrollment, the majority of clients selected Medicare Supplement plans rather than Medicare Advantage. Roughly 87 percent enrolled in Medicare Supplement coverage, while only 13 percent chose Medicare Advantage plans.

This difference is not accidental. It reflects repeated concerns raised during Medicare consultations.

People wanted:

• Broad access to doctors
• Fewer network restrictions
• More predictable out-of-pocket costs

Medicare Supplement plans aligned better with those priorities in this region.

Prescription Drug Changes Drove Most Plan Decisions

Prescription drug coverage was the most common reason Medicare beneficiaries reviewed or changed plans during the 2026 enrollment season.

In many cases, premiums remained stable. Drug coverage did not.

People encountered new medications, tier changes, and pharmacy network disruptions that significantly altered their expected costs. Even small formulary changes forced plan comparisons because the financial impact could be substantial.

One notable development during 2026 was a commonly selected Part D plan dropping to a zero-dollar monthly premium. That shift reduced resistance to switching drug plans and encouraged more active review.

This pattern reinforces a key takeaway. Prescription coverage now plays a larger role in Medicare decisions than premiums alone.

Plan Exits Created Forced Enrollment Activity

Another defining feature of the 2026 Open Enrollment period was plan exits.

Many Medicare beneficiaries did not review their coverage because they wanted to. They reviewed it because they had to.

Plans left service areas. Provider groups exited networks. Hospital access changed. These disruptions forced action, even for people who were satisfied with their prior coverage.

Plan exits are becoming more common as carriers adjust risk and refine geographic footprints. For beneficiaries, this means Medicare coverage can change even when health needs do not.

Provider and Hospital Access Remained Central

Across hundreds of Medicare reviews, provider access was one of the most consistent concerns raised.

People asked practical questions.

• Will my doctor still accept this plan?
• Is my hospital still in network?
• Will I need referrals to see specialists?

These concerns mattered more than extra benefits or promotional features. They also help explain why Medicare Supplement plans remained dominant in Sonoma County during 2026.

Access drove confidence. Restrictions created hesitation.

Sonoma County Compared to State and National Trends

When viewed alongside state and national data, Sonoma County stands apart.

At the national level, Medicare Advantage continues to grow. At the local level, Medicare Supplement coverage remained the preferred option for many beneficiaries who value stability and provider choice.

This gap highlights an important lesson. Medicare is not one market. It behaves differently depending on local healthcare structure, provider availability, and carrier behavior.

Local data provides clarity that broad averages cannot.

What the 2026 Data Means for Medicare Beneficiaries

The 2026 Open Enrollment period reinforced one clear message. Medicare is no longer static.

• Plans change year to year.
• Drug coverage shifts.
• Networks contract.

Beneficiaries who reviewed their coverage annually were better positioned to adapt. Those who did not were more likely to encounter surprises.

Annual review is becoming a practical necessity, not a precaution.

About the 2026 Northern California Medicare Open Enrollment Report

This blog highlights key findings from the full 2026 Northern California Medicare Open Enrollment Annual Report.

The complete report includes:

• Detailed enrollment mix data
• Comparisons to state and national trends
• Analysis of plan change drivers
• Market stability indicators observed during 2026

The report is based on real enrollment decisions from direct client consultations, not surveys or projections.

Download the Full 2026 Medicare Report

This post covers the highlights.
The full report provides the depth.

If you want a clearer understanding of how Medicare actually functioned in Sonoma County during the 2026 Open Enrollment period, the full report delivers that insight.

Download the 2026 Northern California Medicare Open Enrollment Annual Report