I'm outspoken in favor of suitable sized gun in diagonal shoulder holster worn over the T shirt, under the regular shirt . But in order for that to be viable , it requires either button shirt with strategic button " accidentally" left unbuttoned , or Western style snaps . For a scrub style shirt , the off hand would have to raise the shirt tail to armpit level for quick access. Same thing for those compression shirts with built in holsters . So , we're back to belly band or ankle ( or fanny pack ) .
Belly band work best at waist level, just behind strong side hip , aka equivalent to typical IWB placement .
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I don't know the jurisdiction or work environment of the OP , so I'll address a topic generally .
The rules vary widely from state to state ;
1 Actual Law prohibits carry in hospital, etc by catagory .
2. GFZ Signs give Force of Law on their face.
3. Carry addressed in employment contract/ Policies,/ General Orders/ etc, but not illegal per se .
4. Not direct addressed in Employer Policies , but the Management predictably would be major League upset, with significant adverse job consequences.
5. Not addressed in Employer Policies , and you know the Management is somewhere from gun friendly themselves to only being at risk of mild scolding .
Further subdivide # 1 & 2 above if the legal penalties include either mandatory jail time, or make you Prohibited from possessing firearms under Federal Law m