A collapsed lung, also known as a pneumothorax, occurs when air escapes out of a lung and becomes trapped inside the space between the chest and lung cavities. This can be caused by air blisters in the lungs that break open, sudden air pressure changes, or trauma to the chest or ribcage.
The IRS interpreted this provision as applying only to full-time students. In a 1993 technical advice memorandum, the IRS provided a safe-harbor definition of a full-time undergraduate student as one who is taking 12 credit hours and working no more than 20 hours per week.
Version 2002, effective July 1, 2002 Page 3 Part 2: DEFINITIONS AND CLARIFICATIONS Student FTE. A full-time equivalent (SFTE) student equals 30 student credit hours at semester system schools and 45 student credit hours at schools on a quarter system. Colorado Resident Student.