Medicare in Colorado serves about 970,000 beneficiaries, with 49% enrolled in Medicare Advantage and the remainder on Original Medicare + Medigap. Average Medigap Plan G premium for a new 65-year-old enrollee: $143/mo. Stand-alone Part D plans average $44/mo.
Medicare Beneficiaries
970,000
Age 65+ and disabled
MA Enrollment
49%
% on Medicare Advantage
Avg Medigap Plan G
$143/mo
New enrollee, age 65
| Topic | Detail | Notes |
|---|---|---|
| Medicare Advantage plans available | 50+ | Varies by county; check medicare.gov plan finder |
| Top MA carriers | UnitedHealthcare, Humana, Kaiser Permanente Colorado | Networks differ by county |
| Stand-alone Part D | $44/mo | Required if you have Original Medicare + Medigap |
| Annual guaranteed-issue Medigap switching | No (one-time 6-month window at 65) | No state annual GI rights; Kaiser Permanente operates a strong integrated MA plan in the Denver–Boulder corridor. |
Medigap premiums vary by carrier, age, and ZIP code. The 2026 Part B premium is $202.90/month and Part B deductible is $283. Part D out-of-pocket cap is $2,100 in 2026.
Colorado's Medicare market is shaped by a highly active, health-conscious retiree population concentrated in the Front Range (Denver–Boulder–Fort Collins corridor) and resort communities like Aspen, Vail, and Steamboat Springs. Kaiser Permanente Colorado operates a well-regarded MA plan in the metro Denver area, achieving strong quality ratings through its integrated primary care model. UCHealth and SCL Health (now Intermountain Health) are the dominant hospital systems outside Kaiser and are broadly included in UnitedHealthcare and Humana MA networks. Mountain communities present genuine network adequacy challenges for MA plans — Summit County and Pitkin County have limited specialist availability, making Original Medicare with Medigap preferable for beneficiaries in mountain towns.
Colorado's Part D market is competitive with a national average premium of around $44/month. High-altitude resort communities have unique pharmaceutical access considerations — mail-order pharmacy is often the most practical option in ski towns. Beneficiaries moving to Colorado from California should be aware they lose the Birthday Rule upon establishing Colorado residency; Colorado has no analogous protection. The standard 6-month Medigap open enrollment at 65 applies. IRMAA is a meaningful consideration in wealthy communities like Boulder County and Douglas County, where above-average household incomes are common among retirees.
In Colorado, traditional Medicare combined with a Medigap supplement (typically Plan G or N) plus a stand-alone Part D plan provides nationwide access with predictable costs. Plan G covers everything except the $283 Part B deductible.
Medicare Advantage (Part C) plans bundle Medicare Parts A, B, and usually D into one private plan, often with $0 premium beyond Part B. Trade-offs include network restrictions and prior authorization. 49% of Colorado beneficiaries currently choose MA.
No state annual GI rights; Kaiser Permanente operates a strong integrated MA plan in the Denver–Boulder corridor.
💡 Colorado Pro Tip
Colorado beneficiaries in the Denver metro area typically have access to 50 or more Medicare Advantage plans. Mountain counties and rural eastern Colorado may have 15 to 30 options. Kaiser Permanente Colorado, UnitedHealthcare, and Humana are the most prominent carriers in the Front Range market.
The average Medigap Plan G premium for a 65-year-old in Colorado is approximately $143 per month. Denver and suburban metro areas tend to offer competitive rates from multiple carriers, while mountain communities may see slightly higher premiums due to the elevated cost of healthcare in resort areas.
Colorado does not have a birthday rule or annual guaranteed-issue protections for Medigap. Switching outside of your initial 6-month open enrollment period at 65 — or outside a qualifying federal guaranteed-issue event — will require medical underwriting, and carriers can decline you based on health history.
Beneficiary counts and MA enrollment percentages from CMS state-level Medicare data; premium averages from 2026 carrier rate filings for Colorado. Verify current plan costs at medicare.gov before enrolling.
Jennifer Walsh
Editorial Lead, Health & Medicare
This article was researched and written by the Cover Forge USA editorial team against federal sources (NAIC, CMS, FEMA, DOL, SSA, state DOIs) and standard policy forms. Bylines organize content by topic — they do not assert individual licensure. See our editorial-policy for details.
Reviewed May 2026
We monitor rate filings in all 50 states. Get notified when rates change in your area — and discover new ways to save.
Free forever. Unsubscribe with one click. No spam, ever.
Important Disclaimer
This site provides general educational information only and is not a substitute for professional insurance advice. All rates, data, and coverage details are estimates and may not reflect your actual premiums. Insurance availability and pricing vary by state, insurer, and individual risk factors. Always consult a licensed insurance professional in your state before making coverage decisions.