A supplementary health insurance reimburses the portion of medical expenses that the Health Insurance does not cover. This reimbursement can be total or partial depending on the contract taken out. Choosing the right plan requires understanding some technical mechanisms before comparing the available offers.
Reimbursement base and percentages: what a 100% guarantee really means
The guarantees of a supplementary health insurance are often expressed as a percentage. A contract stating “100% optical” suggests that the entire bill will be covered. This is not the case in most situations.
The percentage applies to the reimbursement base of Social Security, not to the actual price charged by the healthcare professional. When an optician charges for equipment at a free price above this base, the difference remains the responsibility of the insured, even with a guarantee advertised at 100%.
To properly assess coverage, one must compare the ceilings and reimbursements expressed in euros, not just the percentages. Examining quotes for services outside the basket allows for measuring the actual out-of-pocket expenses. Detailed information on this subject is available at https://la-complementaire-sante.fr/, which gathers explanations related to the reimbursement mechanisms of mutual insurance.
Medical deductibles and flat-rate contributions: expenses that the mutual insurance does not reimburse

A “responsible” supplementary health insurance contract adheres to a regulatory specification. In exchange for tax benefits, these contracts commit not to reimburse certain expenses. Medical deductibles and flat-rate contributions remain the responsibility of the insured, even with high-end coverage.
The medical deductible applies to medications, paramedical acts, and medical transportation. The flat-rate contribution concerns consultations and certain acts of biology or radiology. These amounts, although modest individually, accumulate over a year.
The increase in these deductibles and flat-rate contributions, initiated by the government to reduce Social Security expenses, has heightened the importance of understanding what the mutual insurance does not cover. A coverage advertised as optimal does not eliminate these everyday expenses.
Dental and optical guarantees outside the 100% Health basket
The 100% Health system guarantees zero out-of-pocket expenses for a basket of dental, optical, and auditory care. This basket covers basic equipment. As soon as the patient chooses care or equipment outside the basket (free price), reimbursements vary significantly from one contract to another.
In dentistry, freely priced prostheses (ceramo-metal crowns on visible teeth, specifically designed bridges) can generate sometimes high out-of-pocket expenses. Checking the guarantees outside the 100% Health basket in dentistry allows for anticipating these expenses before signing a contract.
In optics, high-end frames and progressive lenses regularly exceed reimbursement ceilings. The comparison between mutual insurances should focus on these specific items, not on the care within the basket (already fully covered by all responsible contracts).
- Request a quote from the practitioner before the care and compare it to the mutual insurance guarantee table, checking the amount reimbursed in euros (not just the percentage).
- Identify the annual ceilings by item: some contracts limit optical or dental reimbursement to a fixed amount per year, regardless of the level of guarantee displayed.
- Distinguish the 100% Health basket (guaranteed zero out-of-pocket expenses) from free-price care, where coverage entirely depends on the chosen contract.
Mid-term cancellation: correcting a poor choice of supplementary health insurance

Since the law of July 14, 2019, any insured person can cancel their supplementary health insurance after the first year of the contract, at any time and without charge. This mid-term cancellation has changed the game for insured individuals dissatisfied with their coverage.
Before this reform, a poorly chosen contract forced the insured to wait for the anniversary date to exit. Mid-term cancellation allows for quickly correcting a mismatch between the guarantees taken out and actual needs, without justification or penalty.
In practice, the new organization can handle the cancellation procedures with the former insurer. The transition occurs without interruption of coverage. This mechanism makes the continuous comparison of offers much more relevant than before, as a change remains possible at any time after the first anniversary of the contract.
Responsible contract: a framework that limits reimbursements from above
The vast majority of supplementary health insurances marketed today are responsible contracts. This regulatory label imposes minimum guarantees (minimum reimbursement on certain care) but also ceilings.
A responsible contract cannot reimburse excess fees beyond a certain threshold, nor cover the flat-rate contribution or deductibles. These limitations exist to encourage the use of doctors who practice regulated fees.
For an insured person who regularly consults specialists in sector 2 (free fees), this constraint has a direct impact on out-of-pocket expenses. The choice between responsible and non-responsible contracts deserves to be evaluated on a case-by-case basis, even if non-responsible contracts, which are less common, do not offer the same tax benefits.
The last point to keep in mind concerns the readability of the contract itself. A guarantee table expressed in euros, item by item, remains more reliable than a marketing formula summarized as “level 1, 2, or 3”. Reading the details of exclusions and waiting periods before subscribing avoids disappointments when coverage is actually needed.



