The trade in one sentence
A student loan refinance is a new private loan that pays off the old ones — you win if the new rate is meaningfully lower and you don't need what the old loans provided. For loans that are already private, that second clause is nearly empty: shop rate against rate, mind the term-stretch trap, done. For federal loans, the second clause is everything — a refinance is the permanent, irreversible sale of an insurance policy most borrowers don't notice they own until they need it.
What refinancing federal loans burns, specifically
- Income-driven repayment. Federal plans cap payments at 10-20% of discretionary income and float with your life — job loss, pay cut, new baby, the payment adjusts. Private lenders expect the contractual amount regardless.
- Forgiveness tracks. PSLF wipes remaining balances after 10 years of public-service payments; IDR plans forgive after 20-25. A teacher, nurse, government lawyer or nonprofit worker refinancing out of PSLF can incinerate five or six figures of future forgiveness for a 1.5-point rate cut.
- Deferment, forbearance, and mass relief. Federal loans paused interest-free for three-plus years during COVID; private refis kept billing. Unemployment deferment, cancer deferment, death/disability discharge — the federal system absorbs catastrophe in ways private contracts mostly don't.
The working rule: refinance federal loans only if your income is high and stable, your emergency fund is real (size it first), no forgiveness track applies to your career, and the savings are large enough to pay for surrendering all of the above — a 0.5-point cut isn't; two-plus points on a big balance might be.
The three moves, priced
The calculator's table shows the full menu. Rate-for-rate (same term, lower rate) is the clean win — every saved dollar is real. The stretch (lower payment via a longer term) is cash-flow relief, not savings — often the right call during tight years, but name it honestly: at a lower rate over more years, total interest can still rise. The quiet winner for most strong-credit borrowers is column three: refinance to the lower rate, keep paying the old amount. The payment you're already used to becomes an accelerator — typical result on a $40,000 balance: debt-free 1-2 years early and thousands saved, with zero lifestyle change. It's the same principle as the mortgage extra-payment math, applied automatically.
Getting the best offer
- Rates are credit-priced: the advertised "from 4.5%" belongs to 780-score borrowers with high incomes; real offers spread 2-3 points by credit tier. A qualified cosigner typically cuts 0.5-1.5 points — with the caveat that they're fully liable (look for cosigner-release terms after 12-36 clean payments).
- Shop 3-5 lenders in a two-week window — prequalification soft-pulls don't touch your score, and the hard pulls that follow count as one inquiry within the window. Compare APR (student refis rarely have origination fees, but verify) using the loan comparison calculator.
- Variable-rate offers price ~0.5-1 point below fixed. On a 5-year aggressive payoff, the gamble can pay; on a 15-year term it's carrying rate risk you're not paid enough to hold. Most borrowers should take fixed and sleep.
- Re-refinancing is allowed. Private-to-private refis can repeat whenever rates drop or your credit improves — there's no loyalty prize. Rate-check annually; the second refinance takes an hour.
Who shouldn't refinance at all
Anyone pursuing PSLF or IDR forgiveness — the forgiveness usually dwarfs any rate savings. Anyone whose income wobbles — the federal safety net is worth more than 2 points to a freelancer or seasonal worker (the variable-income crowd knows who they are). Anyone with weak credit right now — offers won't beat current federal rates (recent federal loans at 4-5% often can't be beaten privately at all); build the score first with on-time history, refi later. And anyone counting on employer repayment benefits or state programs tied to loan type. For everyone else, run this calculator's three columns against the baseline payoff plan — the difference between a marketing pitch and a decision is exactly that table.