U.S. Gov't Patent Fees
large - small - micro
Patent Filing Fee$400
Each claim over 20$20
Each independent claim over 3$105
Any multiple dependent claim?$195
Extension - 1 month$50
Extension - 2 months$150
Extension - 3 months$350
Noting Appeal$200
Issue fee$240
Maintenance 4th year$400
Maintenance 8th year$900
Maintenance 12th year$1850

Small entities who have limited income AND have not filed more than four U.S. patent applications can qualify as micro entities