Introduction: Previous studies found that offering free nicotine patches significantly increases calls to quitlines, although most used pre−post designs and did not directly compare the effects of patches and other incentives. The current study with California Medicaid members used a 2 £ 2 design to directly assess the effects of offering free patches and incentives on calls to a quitline. The hypotheses were that offering either would make members more likely to call, and that offering both would increase demand even further. Methods: Flyers were inserted into a mailing sent to 4,268,696 Medicaid households, with one of four offers: (1) free counseling; (2) counseling plus patches; (3) counseling plus a $20 gift card; and (4) counseling plus patches and gift card. Ninety percent received the first offer and 10% received one of the other three offers, in equal proportions. The mailers shipped late 2013 to early 2014. Data were collected 2013−2015 and analyzed 2018. Results: Response rates were 0.029% for counseling, 0.115% for counseling plus patches, 0.122% for counseling plus gift card, and 0.200% for counseling, patches, and gift card. Both patches and gift cards had statistically significant effects (both p < 0.001). Promotional costs were 59%−75% lower with an incentive. Non-whites responded more strongly than whites to a gift card offer. Conclusions: Offering either free patches or a $20 gift card quadrupled the likelihood of Medicaid smokers calling a quitline; offering both had a nearly additive effect. Incentive offers dramatically increased the cost-effectiveness of promotions. Piggybacking on existing Medicaid communications to promote cessation proved very successful. Supplement information: This article is part of a supplement entitled Advancing Smoking Cessation in California's Medicaid Population, which is sponsored by the California Department of Public Health.