- 2501-Introduction
- 2502-2503-[Reserved]
- 2504-Patents Subject to Maintenance Fees
- 2505-[Reserved]
- 2506-Times for Submitting Maintenance Fee Payments
- 2507-2509-[Reserved]
- 2510-Submission of Maintenance Fee Payments and Documents
- 2511-2514-[Reserved]
- 2515-Information Required for Submission of Maintenance Fee Payment
- 2516-2519-[Reserved]
- 2520-Maintenance Fee Amounts
- 2521-[Reserved]
- 2522-Methods of Payment
- 2523-2529-[Reserved]
- 2530-Special Acceptance of Maintenance Fee Payments Containing Informalities
- 2531-Payment Late or Insufficient
- 2532-Duplicate Payments
- 2533-2539-[Reserved]
- 2540-Fee Address for Maintenance Fee Purposes
- 2541-[Reserved]
- 2542-Change of Correspondence Address
- 2543-2549-[Reserved]
- 2550-Entity Status Discounts
- 2551-2559-[Reserved]
- 2560-Revocation of Power of Attorney and Withdrawal of Attorney
- 2561-2569-[Reserved]
- 2570-Maintenance Fee Payment Status Requests
- 2571-2574-[Reserved]
- 2575-Notices
- 2576-2579-[Reserved]
- 2580-Review of Decision Refusing to Accept and Record Payment of a Maintenance Fee Filed Prior to Expiration of Patent
- 2581-2589-[Reserved]
- 2590-Acceptance of Delayed Payment of Maintenance Fee in Expired Patent to Reinstate Patent
- 2591-Intervening Rights in Reinstated Patents
- 2592-2594-[Reserved]
- 2595-Forms