RAP vs IBR: Three Real Borrower Scenarios

"Which plan is cheaper" does not have one answer. Here are three borrowers with different incomes, family sizes, and balances, and why each one lands on a different plan.

Scenario 1: the single parent, low income, chasing PSLF

A public school teacher earns $35,000 a year, has one child, and is pursuing PSLF. Her loan balance is $28,000.

IBR wins here, even though she is a low earner, the group RAP is generally supposed to favor. The reason is family size: IBR's poverty-line exclusion grows with each dependent, and for a family of two, that exclusion outweighs RAP's low starting percentage. Since she is chasing PSLF, forgiveness timeline does not matter, only the lower monthly payment does, so IBR is the better choice for her specifically.

Scenario 2: the mid-career professional, not pursuing PSLF

A private-sector professional earns $85,000 with no dependents and $95,000 in loans at 6.5% interest. She does not work for a PSLF-qualifying employer.

IBR is cheaper per month here too, by about $54. But because she is not pursuing PSLF, the forgiveness timeline matters: IBR forgives in 20 years, RAP in 30. IBR also does not protect her balance from growing if her payment does not cover monthly interest, while RAP guarantees at least $50 of principal reduction every month no matter what. For a borrower planning to pay off the loan rather than ride it to forgiveness, the standard 10-year plan payment (about $1,079/month here) may still beat both if she can afford it, since it avoids extra interest entirely. This is the case where the "cheapest monthly payment" and the "cheapest total cost" answers can diverge.

Scenario 3: the high earner with a small balance, chasing PSLF

A government attorney earns $145,000, has no dependents, and has only $22,000 left on her loans at 6% interest. She is pursuing PSLF.

IBR wins dramatically here, by nearly $1,000 a month. This is the textbook case for IBR's payment cap: her uncapped discretionary-income payment would be over $1,000, but IBR never charges more than the standard 10-year plan would on her balance, and with only $22,000 left, that cap is low. RAP has no equivalent cap and keeps charging 10% of her full AGI regardless of how small her remaining balance is. High income plus a small balance is the single clearest signal to check IBR's cap before assuming RAP is cheaper.

What these three scenarios show

There is no universal winner. Family size can flip the answer at low incomes. Whether you are chasing PSLF changes whether the forgiveness timeline matters at all. And a small balance relative to income can make IBR's payment cap decisive even for earners who "should" favor RAP by the general income-based rule of thumb. Run your own numbers with the combined RAP vs IBR calculator rather than relying on which plan "usually" wins.

Frequently asked questions

Does RAP always win at low income and IBR always win at high income?

No. Family size, loan balance, and interest rate all affect the outcome. A low-income borrower with dependents can find IBR cheaper because of the poverty-line exclusion, and a high earner with a small balance can find IBR cheaper because of its payment cap.

Does forgiveness timeline matter if I am pursuing PSLF?

No. PSLF forgives your balance after 120 qualifying payments regardless of which income-driven plan you used or its own forgiveness timeline. Only your monthly payment amount matters if PSLF is your goal.

When does IBR's payment cap matter most?

When your uncapped discretionary-income payment would exceed what the standard 10-year plan would charge on your balance. This typically happens with higher incomes and smaller remaining balances.

Should I always pick the lower monthly payment?

Only if you are optimizing purely for cash flow or pursuing PSLF. If you plan to pay off your loan rather than seek forgiveness, the plan with the lowest total interest cost, sometimes the standard plan, may be better even with a higher monthly payment.