MPEP Ch. 2500

Question 1

MPEP Ch. 2500

Answer 1

Maintenance Fees

Question 2

Maintenance Fee Due Dates

Answer 2

3.5, 7.5, and 11.5 years after issue date (not filing date). Payments may be made up to 6 months before or after date due. Late payment surcharge.
If patent lapses for failure to pay, can revive if failure was unintentional.