If you qualify for a subsidy
Maryland Health Connection is the most affordable coverage available, full stop. Medicaid is expanded (Maryland Medicaid) in Maryland.
If you don't
Full-price marketplace plans are the most expensive coverage in Maryland. For healthy people, private PPOs on Cigna, Aetna and PHCS PPO are routinely 30–50% less. Maryland has no state penalty for going without coverage, but the state tax return asks whether you had coverage so the state can help uninsured residents enroll.
What's not affordable
Health-sharing ministries and indemnity plans look cheap until you have a claim. Ask for the out-of-pocket maximum; if there isn't one, it isn't insurance.
Maryland runs its own state-based marketplace, Maryland Health Connection, and limits short-term plans to three months with no renewals. Private options here are narrower than in most states, so the honest answer is usually a careful comparison, not a promise of savings.