This article was translated from the original human-written German version. While we strive for accuracy, we cannot guarantee it is error-free. We recommend consulting the German original for the most precise information. This content is for informational purposes only and does not constitute financial or legal advice. Always consult with a qualified professional before making insurance or financial decisions.

Solidarity Principle vs. Equivalence Principle: The Fundamentals of German Health Insurance

The German healthcare system is based on two fundamentally different principles: the solidarity principle of statutory health insurance (GKV) and the equivalence principle of private health insurance (PKV). These principles determine the calculation of contributions, the scope of services, and the type of pension provision within each system.

Understanding these fundamentals is necessary to make an informed decision about one's own healthcare. This article explains the two systems. First, the core features of the solidarity and equivalence principles are presented, then the effects on contributions and services are analyzed, and finally, a summary of the most important systemic differences is given.

1. The Core Principles in Detail

The two pillars of the German healthcare system each follow their own logic in distributing costs and benefits.

Statutory Health Insurance (GKV) and the Solidarity Principle

The GKV is based on the solidarity principle. Contributions are based on financial capacity (income), while services are provided based on individual medical need. People with higher incomes pay higher contributions but, in principle, receive the same medical services as people with lower incomes.

This is financed through the pay-as-you-go system, where current contribution income is directly used to cover current expenses. No significant individual reserves are built up for rising healthcare costs in old age. This system is influenced by demographic development: the ratio of contributors to beneficiaries is a crucial factor for financial stability.

Private Health Insurance (PKV) and the Equivalence Principle

The PKV is based on the equivalence principle. Here, the contribution corresponds to the individual risk and the chosen scope of services. The contribution amount depends on the age of entry, the health status at the time of contract conclusion, and the chosen tariff. Income does not play a role in determining the contribution amount.

For financing, the PKV uses the funded system. A significant portion of the contributions is saved as reserves for aging to compensate for the expected higher healthcare costs in old age. According to the PKV Association, the total of these reserves amounted to around 328 billion euros at the end of 2023. This system is less dependent on demographic development than a pure pay-as-you-go system.

2. Effects on Contributions and Services

The different principles lead to fundamental differences in practice regarding contribution calculation and the scope of services.

Contribution Calculation in Detail

GKV: The contribution is income-dependent up to the contribution assessment ceiling (BBG). For the year 2025, this is €69,300 annually (€5,775 monthly). Every salary increase below this limit automatically leads to a higher contribution. For voluntarily insured individuals, other income sources (e.g., rental income) are also used for contribution calculation. Financing is supplemented by government tax subsidies. The limits are adjusted annually to wage development; the figures for 2026 will be set at the end of 2025.
PKV: The contribution is risk-dependent and based on the age of entry, health status, and tariff choice. Financing is provided without tax subsidies. Individuals with pre-existing conditions may pay a risk surcharge. For employees, access is linked to exceeding the annual income threshold (JAEG), which will be €76,400 in 2026.

Comparison of Service Scope

GKV – Statutorily Defined Scope of Services: The scope of services is uniformly defined by law for everyone in the Social Code Book V (SGB V). According to § 12 SGB V, services must be "sufficient, appropriate, and economical." This catalog of services can be adjusted through political decisions, which has led to changes in the scope of services in the past.
PKV – Contractually Guaranteed Scope of Services: In the PKV, policyholders can determine the scope of services themselves through tariff selection. The services once agreed upon are contractually guaranteed and cannot be unilaterally reduced by the insurer. The scope of services is not tied to the GKV catalog, which can enable access to various treatment methods.

3. System Stability and Contribution Development

Both systems face cost increases but react differently due to their principles.

Contribution Adjustments in Both Systems

Contribution adjustments in both systems are a consequence of medical progress and rising healthcare costs.

In the GKV, adjustments often occur by increasing the contribution assessment ceiling or raising the health fund's individual supplementary contribution.
In the PKV, adjustments are made when costs rise more than anticipated. A contribution increase solely due to aging is legally excluded. The accumulated reserves for aging are used to cushion age-related cost increases.

An analysis by the Scientific Institute of Private Health Insurance (WIP) for the period 2012-2022 showed that the average annual increase in expenses per insured person in the GKV was higher at 3.3% than in the PKV at 2.6%. However, such statistical comparisons are complex and do not reflect individual contribution development.

Summary: The Most Important Key Takeaways

Two Fundamental Principles: GKV is based on the solidarity principle (contribution based on income, service based on need), while PKV follows the equivalence principle (contribution based on risk and scope of services).
Different Financing: GKV uses a pay-as-you-go system without individual retirement planning. PKV is financed through a funded system and builds reserves for aging.
Different Service Promises: GKV offers a statutorily defined scope of services that can be changed politically. PKV offers individually selectable and contractually guaranteed services.
Different Contribution Logic: In GKV, the contribution increases with income (up to the BBG). In PKV, the contribution depends on risk, age, and tariff choice at the time of contract conclusion.

The decision for a system is a fundamental one. It depends on whether one prefers an income-based solidarity system or a risk-based, individualizable system. Both have inherent systemic characteristics that should be considered when choosing the right health insurance.

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Health Insurance: The Differences Between Statutory and Private Health Insurance