You can find the exemption rules under FLSA exemptions at the Department of Labor.
elaws - Fair Labor Standards Act Advisor (http://www.dol.gov/elaws/esa/flsa/screen75.asp)
U.S. Department of Labor - Wage and Hour Division (WHD) - Fact Sheet (http://www.dol.gov/whd/regs/compliance/fairpay/fs17e_computer.htm)
To be eligible for the computer employee exemption the following must be met:
To qualify for the computer employee exemption, the following tests must be met:
The employee must be compensated either on a salary or fee basis at a rate not less than $455 per week or, if compensated on an hourly basis, at a rate not less than $27.63 an hour;
The employee must be employed as a computer systems analyst, computer programmer, software engineer or other similarly skilled worker in the computer field performing the duties described below;
The employees primary duty must consist of:
The application of systems analysis techniques and procedures, including consulting with users, to determine hardware, software or system functional specifications;
The design, development, documentation, analysis, creation, testing or modification of computer systems or programs, including prototypes, based on and related to user or system design specifications;
The design, documentation, testing, creation or modification of computer programs related to machine operating systems; or
A combination of the aforementioned duties, the performance of which requires the same level of skills.
The computer employee exemption does not include employees engaged in the manufacture or repair of computer hardware and related equipment. Employees whose work is highly dependent upon, or facilitated by, the use of computers and computer software programs (e.g., engineers, drafters and others skilled in computer-aided design software), but who are not primarily engaged in computer systems analysis and programming or other similarly skilled computer-related occupations identified in the primary duties test described above, are also not exempt under the computer employee exemption.