This is quite some stuff to work through, because everything in Germany is complex 😀
Travel health insurance or the foreign national health insurance?
This will depend on the legislation in that country, and on what type of job status you will have there. For example for Spain, when being employed or self-employed there, you have to be part of the Seguridad Social public health insurance system and pay fees there (though only ca. 50 EUR monthly) [source]. If you want to avoid that and still want to work, you may have have your business registered in your country of origin and only work telecommute jobs – should generate no problems, though I have no experience with that so far.
When not being part of the foreign national health insurance system, you can get insurance from a private health insurer – either a regular rate that covers also costs abroad, or a specialized travel health insurance (which will be cheaper in nearly all cases).
Selecting an adequate insurer
I have no experience with any of the below, but they'd be the first I would look into.
Travel health insurances:
- Auslandsreiseversicherung der HANSEMERKUR Reiseversicherung. As offered by Mawista GmbH as an intermediate, for example. The special thing about them is that this insurance is possible for up to 5 years in a row, while most other insurers only have a max. duration of one or three years. Costs are a bit higher though, normally 59 EUR monthly (18 – 65 years, without U.S. and Canada).
How to re-enter German health insurance
Once returning to Germany, you have to re-enter the German health insurance system (except you can keep your existing health insurance, which is for example normally possible with travel health insurances for 6 – 12 weeks a year). Here are several options how to re-enter the system, by adequacy:
- As self-employed person: "voluntarily insured member" in public health insurance. This is generally the most recommendable variant. However, public health insurers have to accept you only if you have enough pre-existing health insurance time (de: Vorversicherungszeit). They might still accept you if not, but it's not guaranteed by law. If they do not accept you, you would have to enter private health insurance, given the obligation to have health insurance while in Germany.
The required pre-existing health insurance time is 24 months within the last 5 years [SGB V §9 (1) 1.] This refers to times in the public health insurance only [source], but that should be confirmed again. So when going abroad after 24 or more months of public health insurance, you can stay 3 years without caring about re-entering. To keep your right to re-enter while staying abroad after that, you can re-enter as a voluntarily insured member without entitlement to benefits (because you are abroad). This will cost you about 40 EUR monthly – 2695 EUR * 10% * 14.9% as of 2013 [SGB V §240 (4a), compare Bezugsgröße]. I guess this is what public health insurers usually call "prospective entitlement insurance" (de: Anwartschaftsversicherung). They usually want to tell you to get that type of insurance immediately when going abroad, but that's only needed after three years as reasoned for above.
- As non-employed person. Even without entitlement to become again voluntarily insured in a German public health insurance, you can enter it by leveraging the very law that obliges everybody in Germany to have health insurance since 2009. For that, you have to cancel your self-employment when coming back to Germany, and not take on an employee job either. This makes you a person with obligation to get public health insurance according to SGB V §5 (1) 13. a), and any public health insurance has to take you in. This is sometimes called "Versicherung der ansonsten Nichtversicherten", "Auffangsversicherung" or "Bürgersicherung" in Germany. The rate is the same as for other voluntarily insured members, ca. 130 EUR monthly.
- As employee. This is the simplest case, as all employees are obligatorily insured in the German public health insurance. However, former self-employed people won't like this 😉
- Other options. See the publication "Mitgliedschaft in der gesetzlichen Krankenversicherung nach Auslandsrückkehr" by German Ministry of Health.