Filing for a patent to protect an invention or intellectual property requires detailed knowledge of patent law. An associate patent attorney has extensive experience in the field of patent law and registers with the United States Patent and Trademark Office. Attorneys who register with this office are required to complete specific training and meet other standards that ensure the public they are the best in the field. Patent lawyers can specialize in certain patent areas such as medical patents or utility patents or work on general, across the board patents. When hired, a patent attorney will begin obtaining the information he needs to draft and file for the patent application. At this time, the patent application is put up for prosecution in patent offices around the world. One of the most important jobs of the patent attorney is to determine freedom to operate opinions. Does the product infringe on another patented product? This will require an investigation, which must be complete before the patent filing.