Changes to 14 CFR section 61.23(d) effective on July 24, 2008: Under age 40, airman’s medical certificate duration periods extended:
First-class, 12 months for pilots under 40
6 months for pilots 40 and older.
Second-class, 12 months regardless of age.
Third-class, 60 months (5 years) for pilots under 40
24 months (2 years) for pilots 40 and older.