Aetna vs. Kaiser Permanente (2026 Comparison)

MoneyGeek's analysis of ACA, Medicare Supplement and Medicare Advantage coverage found Aetna and Kaiser Permanente competing directly in only one of the three. Aetna exited the ACA marketplace on January 1, 2026. Kaiser Permanente is the only option for individual market coverage between the two. Aetna is the only choice for Medicare Supplement. In Medicare Advantage, Kaiser Permanente's 4.37 average CMS star rating leads this comparison on quality. Aetna counters on cost: 62% of its plans carry no monthly premium versus 36% for Kaiser Permanente.

As of January 1, 2026, Aetna no longer offers plans on the ACA marketplace. Kaiser Permanente sells HMO and EPO plans in seven states, with premiums below the national average on both plan types. Its overall Quality Rating System (QRS) score is 94.6 and its claim denial rate of 8.3% is well below the 18% national average for ACA health insurers.

Aetna provides Medicare Supplement (Medigap) coverage in 43 states, with seven of the 10 standardized plan types: A, B, C, D, F, G and N. High-deductible versions of Plans F and G are also available. Kaiser Permanente does not offer Medicare Supplement plans, so Aetna is the only choice between the two for Medigap coverage.

Most Aetna Medigap policies use attained-age pricing, so premiums rise every year after enrollment. Plan G starts at $144 per month at 65 and reaches $169 by 75. Plan C costs $276 at 65 and $325 by 75.

Aetna and Kaiser Permanente both offer Medicare Advantage plans, but they serve different priorities. Kaiser Permanente earns an average CMS star rating of 4.37 versus Aetna's 3.88. Aetna counters with broader geographic reach (43 states versus eight) and a higher share of $0-premium plans: 62% of Aetna's plans carry no monthly premium compared to 36% for Kaiser Permanente. Aetna also offers PPO plans, Kaiser Permanente does not.

Medicare Advantage enrollment is limited to specific windows. The Annual Enrollment Period runs from October 15 to December 7 each year. A new Special Enrollment Period applies if you move out of your plan's service area or lose current coverage. Plans rated 4.0 stars or higher also qualify for a Star Rating Special Enrollment Period, which lets members switch to a highly rated plan once between December 8 and November 30. Aetna's 3.41 HMO-POS rating means that plan type doesn't qualify for this window.

Kaiser Permanente is your only option for ACA coverage between the two, with premiums averaging $80 to $183 per month below national averages depending on plan type. Aetna is the only option for Medicare Supplement, with Plan G at $144 per month for a 65-year-old offering the best value in its lineup. For Medicare Advantage, the better choice depends on what you're optimizing for. Aetna's advantage is price, its HMO plans average $7 per month versus Kaiser Permanente's $46, and it operates in 43 states compared to eight. Kaiser Permanente's 4.37 average CMS star rating leads on care quality, nearly a full star above Aetna's 3.41 HMO-POS score. If you're in one of Kaiser Permanente's eight states and have ongoing health needs, the quality difference is worth paying for. If cost is the priority or you live outside that footprint, Aetna is the stronger fit. 

For Medicare Advantage, most beneficiaries who live in Kaiser Permanente's eight states and have ongoing prescriptions or chronic conditions should pay the higher monthly premium for Kaiser Permanente's HMO. The 4.37 CMS star rating reflects real care quality differences. For everyone else, and especially for Medicare beneficiaries in states Kaiser Permanente doesn't serve, Aetna's $0-premium HMO plans are the practical starting point.

We've answered common questions about the difference between Aetna and Kaiser Permanente health insurance across ACA, Medicare Advantage and Medicare Supplement plans :