Texas Insurance Code - INS § 1131.304. Minimum Enrollment

(a) The policy must cover at least 10 employees or members on the date the policy is issued.

(b) A policy as to which the insured employees or members pay part of the premium may take effect only if at least 75 percent of the employees or members eligible on the date the policy takes effect, excluding any employees or members as to whom evidence of individual insurability is not satisfactory to the insurer, elect to make the required contributions.

(c) A group policy issued before September 1, 1969, to a group described by Section 1131.054 that was in existence on that date continues in force without regard to whether the number of the employees or members insured under the policy was less than 75 percent of the employees or members eligible on that date.