BACKGROUND: The Centers for Disease Control and Prevention's US Medical Eligibility Criteria for Contraceptive Use recommends that combined hormonal contraceptives (ie, birth control pills, contraceptive patch, vaginal ring) should be avoided in women with specific medical conditions because of the increased risk of cardiovascular events associated with estrogen use. Whether women with category 3 (theoretical or proven risk usually outweigh the advantages) or category 4 (unacceptable health risk) contraindications are appropriately avoiding estrogen-containing combined hormonal contraceptives is unknown. OBJECTIVE: We describe the prevalence of combined hormonal contraceptive use among a sample of reproductive-age women with medical contraindications to estrogen use. Our hypothesis was that women with categories 3 and 4 contraindications would use estrogen-containing contraception less often than women without medical contraindications. We also explored whether inappropriate estrogen-containing contraceptive use is related to contraceptive provider characteristics. STUDY DESIGN: Data are from the baseline survey of the MyNewOptions study, which included privately insured women residing in Pennsylvania aged 18-40 years, who were sexually active and not intending pregnancy in the next year. Women were surveyed about their medical conditions, contraceptive use, and characteristics of their contraceptive provider. Women were considered to have a contraindication to combined hormonal contraceptives if they reported a category 3 or category 4 contraindication: hypertension, smokers older than age 35 years, a history of venous thromboembolism, diabetes with complications, coronary artery disease, systemic lupus erythematosus with anti-phospholipid antibodies, breast cancer, or migraine headaches with aura. X-2 tests for general association were used to compare combined hormonal contraceptives use, contraceptive health provider characteristics, and sociodemographic data in women with and without contraindications to estrogen use. RESULTS: The MyNewOptions baseline study sample included 987 adult women who were mostly young (46% were 18-25 years), white (94%), employed (70%), and married or cohabiting (54%). Thirteen percent (n = 130) of the sample had a medical contraindication to estrogen-containing contraceptive use: migraine with aura (81%) was the most common contraindication, followed by smokers older than age 35 years (7%), hypertension (11%), history of venous thromboembolism (4%), and diabetes with complications (2%). High use of combined hormonal contraceptives was reported among the women with medical contraindications to estrogen at 39% (n = 51). This was not statistically different from women without a medical contraindication (47%, P = .1). Among the 130 women with a contraindication, whether they did or did not use an estrogen-containing contraceptive did not vary by education level, income, or weight category. With respect to their contraceptive prescribers, there were no differences in prescriber specialty, provider type, or clinic type comparing women using and not using an estrogen-containing contraceptive. CONCLUSION: Among this study sample of reproductive-age women, there was a high rate of combined hormonal contraceptive use in women with a medical contraindication to estrogen use. These women may be at an increased risk for cardiovascular events. Processes need to be improved to ensure that women with medical contraindications to estrogen-containing contraception are being offered the safest and most effective methods, including long-acting reversible contraceptives, such as intrauterine devices and the contraceptive implant.