The above says it's for travel agents, but this one seems more general:
Change/Cancel Fee Amounts
When you book a JetBlue flight, you'll choose from several
fare options — Blue, Blue Plus or Blue Flex — based on what's most valuable to you.
Depending on which fare option you purchased, the change and cancellation fees are as follows:
Blue
Changes and cancellations made 60 days or more
prior to departure date:
- $70 per person fee + difference in fare
Changes and cancellations made
within 60 days of departure date:
- $70 per-person fee for fares under $100 + difference in fare
- $90 per-person fee for fares between $100 - $149 + difference in fare
- $135 per-person fee for fares $150 or more+ difference in fare
Blue Plus
Changes and cancellations made 60 days or more
prior to departure date:
- $60 per-person fee + difference in fare
Changes and cancellations made
within 60 days of departure date:
- $60 per-person fee for fares under $100 + difference in fare
- $80 per-person fee for fares between $100 - $149 + difference in fare
- $120 per-person fee for fares $150 or more+ difference in fare