NICER observation list: Target ID 661701

4U 1850-087 remains as the only persistent ultracompact X-ray binary (UCXB) for which NICER has not yet observed or studied in any detail, which represents a real observational gap given the small number of UCXBs known so far. 4U 1850-087 is a UCXB with a possible 20.6 minute orbital period derived from ultraviolet observations from the Hubble Space Telescope, which has not yet been confirmed with X-ray observations. We propose a 20 ks observation in order to search for millisecond X-ray pulsations from the neutron star primary, establish parameters of the ultracompact orbit, and investigate the physics of mass transfer.