Can I appeal an insurance denial?

Yes - appeal is a formal legal right that comes with your coverage, and insurers are required to make it usable. HealthCare.gov lays out the structure: if your insurer refuses to pay a claim or ends your coverage, you can appeal and have the decision reviewed. Insurers must tell you why they denied the claim and must tell you how to dispute it - that explanation letter is your roadmap, so keep it. The appeal runs in two stages. Stage one is the internal appeal: you ask the insurance company to conduct a full and fair review of its own decision. This is where a letter from your doctor matters most - a specific medical-necessity argument (what was tried, what failed, why this treatment) overturns a large share of denials at this stage. If the case is urgent, the insurer must speed the process up. Stage two is the external review: an independent third party - not the insurer - looks at the denial, and the insurer no longer gets the final say. People skip appeals because they assume the answer is fixed; the published process exists precisely because denials are often wrong, automated, or missing context. Practical tips: mind the deadline in your denial letter (internal appeals typically must be filed within months), submit everything in writing and keep copies, and loop your doctor's office in early - they have done this many times and often have a staffer whose whole job is appeals. Pymander is a free AI doctor, 24/7 by text, and can help you prepare.