USPTO Maintenance Fee Data
This page includes maintenance fee data from the USPTO ( 

Below is a link to a folder that includes all maintenance fee events for patents granted from September 1, 1981 through March 28, 2022. This folder includes ten different zip files. For ease of download and ease of importing, files are divided by patent number. File, “” includes all non-utility patents. File “” includes all patents issued beginning January 1976 through patent number 5,000,000. File “” includes all patents between patent number 5,000,001 and patent number 6,000,000. Etc, etc. This folder also contains a .txt file (“MaintFeeEventsDesc.txt”) that describes each maintenance event.  

Each .tsv file contains the following columns:
Patent number
Application number
Filing date of patent (mm/dd/yyyy)
Issue (grant) date of patent (mm/dd/yyyy)
Maintenance event date of patent (mm/dd/yyyy)
Maintenance event
Y=small entity; M=micro entity; N=large entity

If you have any issues downloading the data, find any problems with the data, or have suggestions for how to make the data better/more user friendly, please let me know: 

Additional USPTO patent data
Abstract, title data can be found here.
Assignee data can be found here.
Citations data can be found here.
Claims data can be found here.
Classifications data can be found here.
Examiner data can be found here.
General info data can be found here.
Inventor data can be found here.
Maintenance fee data can be found here.

Patent-CRSP permco match data
Patent numbers matched to permco numbers data can be found here.