What to do if my employer deducts my hours even though I’m a salary employee but when I work overtime I don’t get compensated?

1) Deducting hours from salaried staff: this is legal only if the employer is debiting a whole day at a time when you miss a day (and do not have or use paid time off, like vacation or sick leave, for it). An employer does not need to pay a salaried employee for days he or she misses, but may not deduct time or pay in less than full-day increments--i.e. if you are late by an hour, or leave two hours early, your employer may not take an hour or two from your pay.

If an employer debits or deducts hours, then under the law, that employee may not be treated as salaried, but rather as hourly--which has implications for overtime (see below).

2) IF you are exempt from overtime, you do not need to be paid overtime when working more than 40 hours in a workweek. To be exempt, two different things must occur:

i) You must be paid on a salary basis--hourly staff are never exempt, which is why, if you must be treated as hourly (because hours are deducted from your pay), you would be eligible for overtime.

ii) You must also meet one or more of the tests for exemption which exist under the Fair Labor Standards Act (FLSA) and its implementing regulations. These tests relate to your job duties (not title--actual responsibilities and authority); even if you are paid on a salary basis, if you don't meet at least one of these tests, you would get overtime when working more than 40 hours in a week.

You can find these tests on the U.S. Department of Labor (DOL) website. The main ones to consider for most staff are the executive (which applies potentially to any manager), administrative, and professional exemptions. You should look these up and compare  to your job duties to see if you may in fact be eligible for  overtime.