Oh, I'm am seeing lots of conflicting info here.

"I think they better to switch S-corp."

Why? For which work? If they are an employee now, why would you change them to carry the full burden as a contracted service provider? If this is for the same work as now, you seem to be overlooking they'll still be an employee, just to a different company (their own S Corp) and now you are proposing they carry all the risk. Do you realize the horrendous malpractice provisions a medical service provider has to navigate? Why would you shift that from the hospital employer to their own S Corp employer?

"It's < $50k before expenses & SEP."

That's one specific person. 

"I thought they have more than $50k after expense, net income"

I don't know if Hope sees that statement presented as a potential rule-of-thumb. That's not an S Corp guidance and that's not Hope's client.

"Besides being an SCorp will only save them on the SE Medicare portion since they are maxing SS through their W-2 wages."

No, it doesn't. Being an employee means there is an employer and an employee share of SS and Medicare. Not being an employee for earned income means the entire amount is the responsibility of the taxpayer, who gets an expense credit for the "employer" share, which is why the 15.3% (6.2% Social Security and 1.45% Medicare, x 2 when you are both the employer and the employee) is reduced on Sched SE (it's a bit recursive). There is the Additional Medicare that is paid from employee only. Moving to an S Corp, as a sole shareholder, means it's still you paying. Now you are paying through your corporate entity. It's still your pocket all of this is coming from; the payer name on the check is different. And being an employee means the employer typically has to pay into Unemployment. And someone, as I mentioned, has to pay all operational costs, such as insurance, benefits, provide for equipment. And now your Doctor likely needs to hire administrative staff, because a Doctor has better things to do than run their S Corp entity and meet all the requirements to keep that solvent and compliant.

401(k) limits are lower than SEP limits. Your Doctor can do work separately from the hospital employer, and that income might qualify for establishing an SEP. That wasn't the question. We were not asked, "How can my Doctor work more, make more, and take advantage of tax breaks?"

And we don't know if this person spends it all, or has investments, and if he has investments, are these the best investment mix to be tax advantaged? Because payroll doesn't have the many options that real life offers, if you want to look for places and ways to leverage some tax breaks.

"TicTok told me to open a corporation so I can deduct my vacations."

Only if you also establish a website. And that is through the same MLM that told you "this one trick no one wants you to know about." OMG, I had a client that went to one of these seminars and bought into all of it, then asked me to consult. I might be the only one that made money in their scheme.

"Could you please give me numbers regarding if wages less than social security max"

I doubt that any Doctor intends to retire on Social Security as their only source of income.