Oscar became the most recent health insurer to slash the commissions it pays to brokers. The Manhattan startup last month sent a letter notifying brokers that rates would be more than halved starting in February. Oscar had planned to pay brokers $14 per contract each month for individual subscribers and up to $26 for enrolled families. Instead, all policies Oscar received after Nov. 6 will generate only $6 a contract per month regardless number of people in the plan, according to the letter. Many former enrollees of collapsed insurer Health Republic of New York have turned to Oscar. Its growing market share only compounds the squeeze on commissions for brokers.