Since 2011, the Deep Carbon Observatory’s (DCO; Deep Life Community has sponsored the Census of Deep Life (CoDL) that has supported surveys of the diversity of microbes present in several deep continental and subseafloor environments. The first surveys (2011-2012) were conducted using 454 pyrosequencing and subsequently (2013) Illumina sequencing strategies were adopted. Through this initiative, the Deep Life Community has allowed the characterization of diversity of subsurface microbial communities at numerous sites worldwide including the subseafloor and deep continental locations from a range of geologic settings (e.g., large igneous provinces, subglacial lakes, methane hydrate-rich sediments, cratons). The Illumina platform provides increased numbers of reads for more samples at reduced cost. For DNA samples submitted to the CoDL for sequencing, proponents have the option of obtaining 400-450 nt sequences that span the V4V5 region of Bacterial and Archaeal rRNA coding regions or a greater number of reads for V6 regions that through complete overlap of forward and reverse reads allows detection of lower abundance taxa with reduced stochastic error rates. Shotgun metagenomic DNA sequencing for key samples can also be performed. This call for proposals aims to support sequencing that represents expanded analyses from ongoing Deep Life Community projects or projects that represent sites and investigators new to the DCO’s Deep Life Community. The proposal deadline is July 15, 2018.