What does it cost to file for and obtain a patent?

Filing a regular U.S. patent application may cost between $5,000 and $10,000. Obtaining an issued patent may require an additional $5,000 to $15,000 for patent prosecution, or more depending on the amount and nature of prior art in the field. Filing and obtaining issued patents in other countries may cost $20,000 or more per country. Also, once a patent is issued in the U.S or in foreign countries, certain maintenance or annuity fees are required to keep the patent alive.