The only tax saving you get is from your bah and bas, which is like 2-3K a year. Negligible in my opinion. I don't even pay attention to your interest rate calculation with the assumption that I will live like a resident and pay back those loan 1st 4 yrs of practice. Again, your financial based decision for HPSP wasn't very well thought out.
To pay off a 6%, 500K loan (Perrotfish's example that you quoted) in 4 years requires an $11,742 per month payment. Even with that accelerated payment plan, the cost still includes another $63K of interest.
So that's $140,910 in payments per year ... if you add, say, $60K of after-tax money to spend on "living like a resident" then you need $200K of after-tax money. If you're MFJ living in a high tax state like California that requires an income of about $318,000 W2.
That's $318K
- $80K in federal taxes (effective rate just over 25%)
- $12K in payroll taxes, 6.2% for the first $118,500 plus 1.45% medicare (no cap)
- $25K in state taxes
Note this leaves ZERO room for any retirement savings or investing. Why don't we go ahead and make the assumption that if you're motivated and responsible enough to pay off student loans in 4 short years, you're not going to leave tax-deferred saving space unused. Even if all you've got available is a sad little employer 401(k) with an $18K limit, now you need an income of $336K.
A couple of bold assumptions you're making:
#1 That one can count on finding a W2 position paying $336K right out of residency, regardless of specialty. Remember, pre-meds don't know what specialty they'll end up in. For every successful ENT or ortho spine surgeon in the world, there are 10 premeds who think that's their destiny but wind up in attainable but lower paying specialties.
#2 That after spending med school and residency working like a dog and living in near poverty, that you'll choose to keep living that way despite a fat $336K salary. And that your family will be up for extending the poverty ride too. Be honest. 9/10 people can't do that.
Could you? Well, you're a "finance guy" who supposedly made 15% year over year, year after year just by being a clever Warren Buffet baller in the stock market, so assuming that actually happened and you're not exaggerating your gains or conveniently forgetting about losses, then you're a risk taker. So, why pay the loans back at an accelerated rate at all? You're a "finance guy" ... why pay back a loan accruing 6% when you can earn 15% in the market? Be honest. You wouldn't do it either.
The simple, real world truth is that to pay off a $500K loan in four years, the young doctor needs a job around $400K, leaving about $100K post-tax, post-401k, post-loanpayment in order to live
a little bit above the resident lifestyle.
Now. How many doctors exit residency and walk into $400K+ W2 positions? How many premeds would you advise to bet that's what their future holds?
(For a 1099 contractor position the roughly equivalent contract is about $458K, which assumes a $53K pre-tax contribution to a SEP-IRA instead of the $18K 401(k) ... but doesn't account for health insurance costs, malpractice premiums, or other W2 benefits. Probably need $500K+ 1099.)
Still think $500K in loans is no big deal?
As for your assessment of the tax advantages of being a military physician being "like $2-3K per year" ... what? Even if you don't cherrypick the high BAH of San Diego or DC, you're still probably looking at a minimum $1.5 - 2K/month BAH most places. No fed/payroll taxes on that is somewhere around $6K of tax savings. Then there's no state tax to pay ... not just on the BAH but on the entire paycheck. For a residence in CA that's easily a $10K+ benefit depending on the size of the underlying paycheck.
Since we're talking about people who do their time and get out, I won't get into the details of the tax implications of a military retirement, and the value of pre-tax employer contributions to defined benefit plans. But for those who stay, it's low-7-figure value with a 6-figure tax benefit.
God knows I'm not here trying to talk people into joining the military, but if you're going to make arguments based on math, you've got to do the math correctly. The numbers are what they are. (Unless Congress changes them in the 8+ years between our premed's matriculation and graduation from residency ... adding
even more risk to the equation.)