Whether to pay off student loans or invest depends on two numbers: the loan's rate and the after-tax return you'd assume. Annex Wealth Management then tests both against the date your next big bill arrives. Most people compare the loan rate with the market's average return. A taxable account has to be counted after tax: a 6% assumed return that loses a quarter to tax nets 4.5%, below a 6% private loan. The exact split depends on your loan contract, tax picture and bill dates; the arithmetic does not. When Annex Wealth Management reviews a household's first comparison, the tuition date and the monthly cash actually left over are the two items most often missing.
Step 1: Gather the loan statement, the 1098-E and three months of spending
Start with the private servicer's latest statement, not the refinance offer email. It lists the current rate, whether it can change, the reset date if it is variable, the payoff amount and how extra payments are applied. Call the servicer and ask it to send extra money to principal, not to move your next due date.
The $4,000 must be what remains after real spending. Total up a full quarter of checking and credit card activity, then mark when the next large bill arrives. For Farid, the first tuition bill is due in three years. Annex Wealth Management builds this monthly spending plan first and only then proposes how to divide the spare cash.
The servicer sends Form 1098-E in January; it reports interest paid. Last year's tax return shows adjusted gross income, or AGI, which helps your CPA check whether any student loan interest deduction remains at your income. If you work for an employer, pull the plan's summary plan description for its match formula and vesting schedule.
Using a rate remembered from a refinance email can wreck the comparison. A variable loan quoted at its starting rate may already have a reset date and a higher cap.
Step 2: Is your private loan rate above the after-tax return you'd assume?
Compare the loan rate with an assumed return after tax; nobody can forecast the actual return. At an assumed 6% return, losing a quarter of the gain to tax leaves 4.5% in a taxable account. If the loan rate beats that by more than one percentage point, extra payments usually win.
If it trails by more than one point, investing usually wins. Within one point, split the spare cash. Treat a variable rate as though it had already reached its cap. Capture a full employer match first, and fund an available pre-tax plan before accelerating the loan. Farid's 6% loan sits 1.5 points above the 4.5% figure, which points most of his $4,000 toward the loan, though no investment result is promised.
For this comparison, a private loan is different from federal debt on an income-driven plan or headed for Public Service Loan Forgiveness (PSLF). Prepaying those federal loans can reduce the balance that may be forgiven, so make only required payments while checking the program rules. The math here also does not settle a separate loan for buying or running a dental practice.
| If | Then the $4,000 goes | Why |
|---|---|---|
| Employer match not yet captured | Enough for the full match first | Match is an immediate return |
| Loan rate above after-tax return | Mostly to the private loan | Guaranteed 6% beats assumed 4.5% |
| Rates within one point | About half and half | Interest drops from $83,000 to $41,000 |
| Loan rate below after-tax return | Mostly to investing | Expected gap favors the portfolio |
| Big bill due within three years | That sum into cash first | A market drop can't reach it |
| Federal loans heading to PSLF | Required payment only | Prepaying shrinks the forgiven balance |
Step 3: Run three splits of the $4,000 against the tuition date
Farid, a hypothetical 51-year-old general dentist, owns a four-chair practice set up as an S corporation. He owes $250,000 on a refinanced private dental school loan at 6%, and his child starts college in three years. His scheduled ten-year payment is about $2,775 each month; he has another $4,000 to direct. In month one, interest is $250,000 × 6% ÷ 12 = $1,250. If he makes only the scheduled payments, 120 × $2,775 = $333,000 total, including $83,000 in interest.
With the full $4,000 going to an investment account, Farid keeps paying $2,775 to the loan on schedule. That path costs about $83,000 in loan interest. With half the extra cash going to the loan, his loan payment becomes $4,775 each month; the loan clears in about 61 months, with roughly $41,000 in interest. With all $4,000 going to the loan, he pays $6,775 each month and clears it in about 41 months, paying roughly $27,000 in interest. From month 42, the freed $6,775 each month can go to cash or investing.
Over ten years, assuming a 6% annual return before tax for illustration, all three splits end with roughly $655,000 invested under the stated comparison. The loan rate equals that assumed return, so the pre-tax math is roughly even. In a taxable account, if a quarter of the gain goes to tax, prepaying at 6% comes out ahead on this simplified comparison. Investments can fall in value, and Farid could get back less than he invested; a loan payment cannot do that.
But the first tuition bill arrives at month 36. If Farid directs all spare cash to the loan, about $33,000 is still owed then, and he has set aside nothing for the first semester. A version that fits his spending plan holds the first year's tuition in cash, then sends the remaining spare amount to the loan; the freed payment can cover later semesters. Reading 'be debt-free before you invest' as 'send every spare dollar to the loan' leaves Farid short, so tuition may land on a new loan or the practice credit line. The figures are rounded; the exact payoff depends on the servicer's daily interest and payment timing.
The $655,000 comparison assumes each path invests the same available cash at the same assumed rate. It is not a market forecast or a precise account balance. A different tax bill, loan reset, tuition amount or investment result changes the comparison. Annex Wealth Management sets the month-36 tuition date next to the loan balance, since the portfolio's job is to pay for the spending plan.
| Split | Loan interest | Payoff month | Cash at month 36 |
|---|---|---|---|
| Invest all extra | About $83,000 | Month 120 | No tuition reserve |
| Half to loan | About $41,000 | About month 61 | Depends on reserve |
| All extra to loan | About $27,000 | About month 41 | None set aside |
Step 4: Which comes first, the January 1098-E, April 15, the rate reset or December 31?
January brings the 1098-E and year-end account statements. April 15 is the federal tax filing deadline and the last day for prior-year IRA contributions. Mark the variable-rate reset date from the loan statement, wherever it falls in the calendar.
Around October 1, the FAFSA opens and uses tax information from two years earlier, so income in the years before college can affect aid calculations. December 31 is the last day for that year's 401(k) or 403(b) salary deferrals.
Paying extra before three to six months of spending sits in cash is too early. Waiting until a variable rate resets higher can be too late. Sending extra to debt before collecting the full employer match gets the order wrong; that match is an immediate return, subject to vesting. Make extra payments alongside the regular monthly bill, not as a year-end lump. Student-loan interest accrues daily, so each month's principal payment starts reducing interest sooner. Annex Wealth Management checks the plan deadline and loan reset against the dates the household needs cash.
Step 5: Talk it over at home, then leave room for a bad year
The spouse who pays the bills or watches account balances often raises the question first. Talk over the monthly spending number and tuition date, not net worth. Agree on a cash floor that extra payments cannot cross. Money sent to principal usually cannot be pulled back, so hold three to six months of spending in cash before speeding up repayment.
Keep money due within three years out of the market; a drop just before tuition can force a sale at a loss. Check the private loan agreement for death and disability discharge terms, since lenders differ. The disability insurance article covers the income side of that risk. Tax deductions and refinance choices can change, too. Annex Wealth Management sets the cash floor before any extra payment is scheduled, so the loan only gets what is left above it.
- Check the loan's death and disability terms
- Keep tuition due soon in cash
- Ask the CPA about deductible interest
- Confirm extra payments reduce principal
- Check the match and vesting rules
- Ask the advisor about return assumptions
Where Annex Wealth Management starts with a loan-or-invest question
Annex Wealth Management starts with the monthly spending plan and the next large bill dates, such as a tuition bill due at month 36. From there, the firm helps decide how much spare cash goes to the loan, to cash and to investing. Fees are set out in a signed agreement before work begins. You can ask for a first conversation through the site's request form; bring the loan statement and three months of spending.
Questions about pay off student loans or invest
My Form 1098-E shows thousands in student loan interest, so can I deduct it on a doctor's income?
Should extra cash go to a 6% private student loan or to the dental practice loan?
How soon after the private loan is paid off should the freed payment start going into investments?
What happens if I lose income after sending every spare dollar to my student loan?
Primary sources
This material is general information only and does not constitute investment, tax or legal advice tailored to your circumstances. Investing involves risk, including possible loss of principal. Before acting on any information here, speak with a financial advisor, tax professional or attorney about your specific situation.