You must have compliant Travel Insurance for all of your trips to avoid problems during border controls and in the event of a medical incident.
Regulation (EC) No 810/2009 of the European Parliament and of the Council of 13 July 2009, establishing a Community Code on Visas (Visa Code):
Article 15
“ Travel medical insurance
[…]
2. Applicants for a uniform visa for more than two entries (multiple entries) shall prove that they are in possession of adequate and valid travel medical insurance covering the period of their first intended visit.
In addition, such applicants shall sign the statement, set out in the application form, declaring that they are aware of the need to be in possession of travel medical insurance for subsequent stays."
For your information, if you make several trips during the year, we offer an annual plan that can be renewed automatically.
All our travel insurances are compliant for Schengen visa applications.
Nevertheless, some Embassy can have specific requirements depending on the type of visa you applying for (especially about deductible).
We invite you to check with your visa center.