Yes, provided you are not yet 55 years of age, and you are required to have health insurance. However, switching back to public health insurance may have its disadvantages. We would be happy to advise you on the subject. It's much harder to switch from the age of 55. Lawmakers have taken measures in this regard by introducing the basic coverage plan (Basistarif).
The so-called basic coverage plan was introduced in 2009. The basic coverage plan is like public health insurance in the private sector for private policyholders who are unable to pay their premiums, or who do not wish to pay more than they would for public health insurance. The coverage is identical to that offered by public health insurance. If you are in need of assistance, you may switch from a normal plan to the basic coverage plan.
If you don't wish to pay more than you would for public health insurance, you may do so from the age of 55 even if you are not in need of assistance. Thanks to the old-age provisions which you have accumulated over a long policy term, your basic coverage plan premium will be significantly below the maximum premium you would pay for public health insurance.