NMRA Achievement Program
While participation is strictly voluntary, all NMRA members are welcomed and encouraged to participate in the Achievement Program.
The Achievement Program is an educational program in which you learn and demonstrate mastery of the many crafts and skills necessary
in the hobby of model railroading.
The ultimate honor bestowed by the Achievement Program is the title of MASTER MODEL RAILROADER (MMR). An NMRA member qualifies as a MMR when he or she has obtained at least seven of the eleven Achievement Certificates provided that there is at least one in each of the four achievement categories of the Regulations. More specific information is in the pages at the links above.
In addition, you can see all the details on the NMRA website located at this link.