February 21, 2005, Revised December 28, 2005, June 4, 2009
An interest-only mortgage (IO) is one that grants the borrower an option
to pay only the interest for the first 5-10 years. They can pay more if
they wish, but they are obliged to pay only the interest. IOs have been
around for a long time, but their recent popularity began when the
option was attached to adjustable rate mortgages (ARMs).
Some of this popularity is based on a misperception. Since ARMs have
lower rates than fixed-rate mortgages (FRMs), IOs are marketed as having
low rates. Since a 30-year ARM with an IO option is priced lower than a
30-year FRM, for example, the lower rate is attributed to the IO. Few
loan providers bother to mention that an ARM with the IO option is
priced higher than the identical ARM without the option.
Every time I think I have shot down the last of the exaggerated claims
for interest-only, a new one pops up. Here is the latest.
"I am planning to purchase a house and sell it within 1 or 2 years. I
have been advised that an interest-only loan fits this situation best.
Is that true?"
An interest-only (IO) is the instrument of choice in a quick turnover
situation only if you are trying to maximize the amount of house you can
buy, and are limited by your income. The IO option lowers the required
initial payment, which allows you to qualify for a larger loan amount.
This is why buyers in markets undergoing strong price appreciation, who
are looking for quick capital gains, gravitate to IOs – or to their big
brother, the flexible payment (option ARM), which has even lower
payments in the first year than an IO. See Option (Flexible Payment)
ARMs.
The more expensive the house they can buy, the larger the expected
capital gain. However, if you don’t need an IO to qualify for the house
you want to buy, it is not the best choice in a quick turnover
situation.
Your objective should be to minimize your total net costs over the 1-2
years you have the mortgage. Gross costs include points and settlement
costs, which are paid upfront, monthly payments during the period, and
interest lost on both upfront costs and monthly payments. Cost offsets
that are deducted from the total consist of tax savings and reduction in
the loan balance.
Whether or not the mortgage is an IO hardly affects total net costs. The
payment is lower with the IO, but balance reduction, which is a cost
offset, is eliminated.
To minimize total net cost over a short period, focus on finding the
best combination of interest rate and rebate. A rebate is negative
points, where the lender pays you for a higher rate instead of you
paying the lender for a lower rate. A rebate will reduce or perhaps
eliminate your upfront cost. When your time horizon is very short,
paying a higher interest rate in exchange for a rebate is a good deal
because you won’t be paying the rate very long.
To verify this, on December 17, 2005 I accessed a data base on wholesale
prices posted by the major wholesale lenders – those that deal with
mortgage brokers. I shopped (as if I were a broker) for a conforming
loan of $300,000 on a $400,000 house purchase for a borrower with good
credit, who can fully document adequate income and assets, and who will
occupy the house as a permanent residence.
I found the best deal on 15 and 30-year fixed-rate mortgages (FRMs), and
3, 5 and 7-year adjustables (ARMs), each with and without an
interest-only option, at the highest rebates offered. I then used
calculator 9ci to find the total costs over a 2-year period in all 10
cases. As a check, I did the same thing at zero points and at the
largest number of points offered.
The lowest cost mortgage over 2 years was the 15-year FRM with the
highest rate-largest rebate combination. A close second was the 30-year
FRM with the highest rate-largest rebate combination. On the ARMs, in
contrast, costs were not materially different between the highest
rate-largest rebate combination and the combination of a lower rate at
zero points. In every case, switching to the IO version, whether FRM or
ARM, increased the cost.
You can’t shop wholesale prices, but the relationships I found will
carry over to web sites you can shop, such as
those of the 7 Upfront
Mortgage Lenders. If your time
horizon is 2 years, your instrument of choice is a 15-year FRM with the
largest rebate offered. If you can’t make the payment on the 15, your
second choice is the 30-year FRM with the largest rebate. Neither ARMs
nor IOs work as well.
Note that the calculation of total cost is impacted by your tax rate,
which affects tax savings, and your savings rate, which affects interest
loss on upfront costs and monthly payments. However, you can adjust
everything to the particulars of your personal finances using calculator
9ci,
Future Value Calculator:
Comparing Two Fixed-Rate Mortgages.
This calculator offers an interest-only option, so if you aren’t
convinced that interest-only won’t minimize your costs, you can test it
yourself. Just remember that when you use the IO option, you must adjust
the price as well. Adding an IO option always increases the price.