To apply for USPTA membership or register for an exam, you must pay both the application fee and the appropriate prorated dues amount.

Membership Application Fee for Certified Professional(Nonrefundable fee includes application processing, review course and study materials that are emailed to you. You will also receive a new member package.)
United States, its territories and Canada $399
International members $275

Plus, Applicable Dues:
Annual Professional Dues of $315 must be paid by all current professional members by the end of December of the previous year. If a member joins once the new year has already begun, the prorated amount will be charged as follows:

Prorated Dues
(Nonrefundable and prorated to the month in which you apply)

Applying for membership Domestic Professionals Tennis Instructors International Professionals
$288.75 $197.08 $160.42
February  $262.50 $179.17 $145.83
March  $236.25 $161.25 $131.25
April  $210.00 $143.33 $116.67
May  $183.75 $125.42 $102.08
June  $157.50 $107.50 $87.50
July  $131.25 $89.58 $72.91
August  $105.00 $71.67 $58.33
September  $78.75 $53.75 $43.75