I initially posted this as an answer, but in context AllegroTrans's suggestion, "is living", is clearly right (see the example in the Wikipedia page cited below). However, the references I found, establishing what this kind of document is called in English, may be of interest:

"certificate of existence
A document signed by a responsible person saying that someone who is going to receive a pension is still alive."
Source: Longman Business English Dictionary
http://lexicon.ft.com/Term?term=certificate-of-existence

"A Certificate of Life (also called a Proof of Life, Certificate of Existence or Letter of Existence) is a certificate produced by an embassy or other government body to confirm that an individual is still alive.

Governments, pension and insurance companies and other bodies may need to check periodically that the people they are paying have not died in order that they do not overpay annuities and pensions."
http://en.wikipedia.org/wiki/Certificate_of_life

"Life certificate" was previously chosen here as a translation of "certificado de supervivencia"
http://www.proz.com/kudoz/spanish_to_english/law_general/114...

But personally I like "verification of non-decease"; the trouble is I've only found it in one place:
"The 1808 [Life Annuity] Act
[...] Nominees had to be at least 35 years of age, and annuity yields were
capped at age 75, strongly discouraging purchases by older annuitants. A
minister- or magistrate-certifi ed register of birth or baptism was required
for age veri fication. Veri fication of non-decease was required for receipt of
each payment."
http://www.stanford.edu/group/SITE/SITE_2008/segment_4/paper...