These bars apply not only to unauthorized employment since an applicant’s most recent entry but also to unauthorized employment during any previous periods of stay in the United States. 
As previously discussed, the INA 245(c)(2) and INA 245(c)(8) bars to adjustment do not apply to: 
- Immediate relatives;
- Violence Against Women Act (VAWA)-based applicants;
- Certain physicians and their accompanying spouse and children;
- Certain G-4 international organization employees, NATO-6 employees, and their family members;
- Special immigrant juveniles; or
- Certain members of the U.S. armed forces and their accompanying spouse and children.
Employment-based applicants also may be eligible for exemption from this bar under INA 245(k). 
Calculating the Period of Unauthorized Employment for I.N.A. Section 245(k)Be careful in calculating your period of unauthorized employment in the United States.
For purposes of Section 245(k), it begins on the day you were hired and ends on the day employment is terminated, or the day you were granted legal authorization to work.
If you worked for multiple employers without authorization at different times after entering the United States, all periods of employment will be added together and count towards the 180 days.
One common mistake applicants make is omitting weekends, vacation days, and sick time from their period of unauthorized employment.
Unfortunately, these days count towards the 180-day total, even though you were not actually performing work.
For example, if you did not work for a total of 30 days in a 181-day period, you will not satisfy Section 245(k) because those days off will count towards the total and your period of employment will have exceeded 180 days.
Another common mistake is assuming that unpaid employment does not count as unauthorized employment. Employment is not necessarily defined by compensation. Any position that does not truly qualify as volunteer work can be viewed as employment, even if you are not compensated for it. If this is your situation, consult with an immigration attorney to determine whether or not you did engage in unauthorized employment.