This document summarizes lessons learned from scaling up the Standard Days Method family planning intervention in 5 countries over 10 years. Key lessons include: (1) Define scale-up outcomes operationally and contextually; (2) Tools and guidance may need further simplification for scale-up; (3) Repeat evidence of the method's effectiveness throughout; (4) Start promotion early and ensure parity with other methods; (5) Develop temporary monitoring until integrated into health systems; and (6) Continually monitor that gains are not reversed by changing systems. Documenting scale-up challenges can help refine knowledge and help others.