Since 1 January 2023, there has been the Versicherungsnummernachweis (insurance number certificate, formerly Sozialversicherungsausweis). It contains the following information: Insurance number, first name(s), surname, surname at birth and the date of issue. Employees receive it automatically when they take up their first job. You need the insurance number certificate to identify yourself for social insurance purposes. Old social security cards are still valid. Employees who live in the Netherlands or Belgium, for example, and are subject to German social security law, will also receive an insurance number and proof of insurance number.
In the event of loss, destruction or unusability, a new proof of insurance number can be applied for via the online services of Deutsche Rentenversicherung – free of charge and without any fees.
You can find more information on this on the Deutsche Rentenversicherung website.