To add to JoeTaxpayer's answer, the cost of providing (term) life insurance for one year increases with the age of the insured. Thus, if you buy a 30-year term policy with level premiums (the premium is the same for 30 years) then, during
the earlier years, you pay more than the cost to the insurance company for providing the benefit. In later years,
you pay somewhat less than the cost of providing the insurance. The
excess premiums that the insurance company charged in earlier years and the earnings from investing that money covers the difference between the
premium paid in later years and the true cost of providing the coverage.
If after 20 years you decide
that you no longer need the protection (children have grown up and now
have jobs etc) and you cancel the policy, you will have overpaid for the
protection that you got. The insurance company will not give you backsies
on the overpayment.
As an alternative, you might want to consider a term life insurance policy
in which the premiums increase each year (or increase every 5 years) and thus
better approximate the actual cost to the insurance company. One advantage is
that you pay less in early life and pay more in later years (when hopefully
your income will have increased and you can afford to pay more). Thus,
you can get a policy with a larger face
value (150K for your wife and 400K for yourself is really quite small) with
annual premium of $550 now and more in later years. Also
if you decide to cancel the policy after 20 years, you will
not have overpaid for the level of coverage provided.
Finally, in addition to a policy with larger face value, I recommend
that you include the mortgage (if any) on your house in the amount
that you decide is enough for your family to live on and to send the
kids to college, etc., or get a separate (term life insurance)
policy to cover the mortgage on
your home. Many mortgage contracts have clauses to the effect that
the entire principal owed becomes immediately due if either of the
borrowers dies. Yes, the widow or widower can get a replacement
mortgage, or prove to the lender that the monthly payments will
continue as before, (or pay off the mortgage from that $150K or
$400K which will leave a heck of a lot less for the family to
survive on) etc., but in the middle of dealing with all
the hassles created by a death in the family, this is one headache
that can be taken care of now. The advantage of including the mortgage
amount in a single policy that will support the family when you
are gone is that you get a bit of a break; the sum of the annual
premiums on ten policies for $100K is more than the premiums
for a single $1M policy. There is also the consideration that the
principal owed on the mortgage declines over the years (very slowly
at first, though) and so there will be more money available for
living expenses in later years. Alternatively, consider a special
term life insurance policy geared towards mortgage coverage.
The face value of this policy reduces each year to match the
amount still due on the mortgage. Note that you may already
have such a policy in place because the lender has insisted on
you getting such a policy as a condition for issuing the loan.
In this case, keep in mind that not only is the lender the
beneficiary of such a policy, but
if you bought the policy through the lender, you are providing
extra profit to the lender; you can get a similar policy at
lower premiums on the open market than the policy that your
lender has so thoughtfully provided you. I bought mine from
a source that caters to employees of nonprofit organizations
and public sector employees; your mileage may vary.