1525 Background: Over 90% of oncologists agree that sperm banking should be offered to all men at risk of subfertility associated with cancer treatment, but fewer than 50% bring up the topic. Barriers cited include lack of time for the discussion, perceived high cost, and lack of convenient facilities. The advent of mail-in semen analysis (SA) testing and cryopreservation may improve access to this service via lower patient cost, decreased required oncologist logistical support, and home rather than local lab collection. That said, average sperm recovery rate after sample thaw is ~50% with immediate banking, and sperm recovery rate after delayed cryopreservation with a mail-in approach remains unknown. Methods: This is a prospective preliminary study assessing freeze-thaw total motile count at 3 time points of cryopreservation: upon receipt of sample, at 24 hours, and at 48 hours post collection. We collected 39 fresh semen samples from 13 healthy adult volunteers. Samples were diluted with 5mL of Fellow Health preservation solution and analyzed (World Health Organization guidelines V5). Samples were divided into 3 aliquots: Aliquot #1, T0 was immediately frozen with equal part cryoprotectant. Aliquot #2, T24 and aliquot #3, T48 were left at room temperature for 24 and 48 hrs respectively, analyzed, and then frozen. Aliquots were then thawed on a heat block at 37C for 10 minutes and analyzed. Results: Baseline SA values were: volume 3.3ml +/- 1.3, concentration 138.3 +/-57.4 x 106, motility 49% +/-6%; Total Motile Count (TMC) 213 +/- 110 million. TMC was the primary endpoint as measured by baseline semen volume, concentration, and motility at 3 time points (T0, T24, T48). The average loss from freeze/thaw in TMC at T0 was 45%, at T24 was 55% relative to T24 pre-freeze, and at T48 was 59% relative to T48 pre-freeze (p = 0.013). On average, samples with starting TMC between 50-100 million had enough motile sperm for six intrauterine insemination (IUI) cycles when frozen and thawed at T0, two at T24, and two at T48. Samples with starting TMC between 100-200 million had enough motile sperm for 16 IUI cycles when frozen and thawed at T0, eight at T24, and four at T48. Samples with starting TMC > 200 million had enough motile sperm for 42 IUI cycles when frozen and thawed at T0, 21 at T24, and nine at T48. All samples had ample viable cells ( > 50,000) at all three time points for in vitro fertilization (IVF). Conclusions: Mail-in cryopreservation using our improved methodology may increase access to this service for oncological patients while still facilitating reasonable assisted reproductive technology care relative to in-person cryopreservation.