Here is the main text of the two items cut from the on-line pdf copy of the Shield manual - "Warranty" & "Service Policy". The difference appears to be in exclusions after the first year.
http://www.smith-wesson.com/wcsstore/SmWesson2/upload/other/MP_Shield_Manual_11-11-2015.pdf
This warranty is granted by Smith & Wesson Corp. This warranty
is effective from the date of purchase and applies to the original
owner of any firearm. With respect to such firearms, this warranty
supersedes any and all other warranties.
Smith & Wesson firearms are warranted to be free from defects
in material and workmanship. Any such defects of which Smith
& Wesson receives written notice within one year from the date
of purchase by the original owner, will be remedied by Smith &
Wesson without charge within a reasonable time after such notification
and delivery of the firearm as provided below.
In the event of an emergency (repairs needed by law enforcement,
an upcoming match or hunting trip), call 1-800-331-0852,
ext. 4125 and ask for 911 Priority Repair Service. This allows
you to speak with a Smith & Wesson representative.
Immediately upon receipt, your firearm will be assigned to a gunsmith.
After the work is completed, we will return your Smith &
Wesson firearm via overnight delivery.
Warranty claims (in writing) and the firearm concerned should be
delivered to Smith & Wesson’s Customer Service Department,
2100 Roosevelt Avenue, Springfield, Massachusetts 01104. In
addition, a copy of the bill of sale in the owner’s name, or a copy
of ATF Form 4473 indicating date of purchase must be included.
It is important that the owner comply with all applicable federal,
state and local laws and regulations in the shipment of firearms
to Smith & Wesson.
- - -
Smith & Wesson’s Lifetime Service Policy begins after the warranty
period has expired. Smith & Wesson will repair, without
charge, for the lifetime of the original owner, any Smith &
Wesson handgun purchased on or after February 1, 1989, and
any M&P series rifles, that is found to have a defect in material
or workmanship. Eligibility for this Lifetime Service Policy
requires returning the Product Registration Card within 30 days
of purchase. The Lifetime Service Policy covers functional
defects; it does not include the firearm’s finish, grips, magazines
or sights. The Lifetime Service Policy is in addition to and not
an extension of the Smith & Wesson Warranty.