What does an infectious disease doctor do?
An infectious disease doctor is a doctor who diagnoses and treats infections that are hard to identify or treat. They also manage long-term infections such as HIV.
Last updated November 11, 2026
Find infectious disease doctors near you
When people see one
- An infection that does not clear with the usual antibiotics
- A fever with no known cause
- HIV care or prevention
- A hospital stay that involved a serious infection
How it differs
Internal medicine doctor: An internist treats common infections along with other adult conditions. An infectious disease doctor takes on the unusual, resistant, or long-lasting ones.
Pulmonologist (lung doctor): Both can treat lung infections such as pneumonia or tuberculosis. A pulmonologist focuses on the lungs; an infectious disease doctor on the germ.
On 2027 Colorado plans
Do you need a referral? On some plans. 37 of the 148 2027 plans need a referral from your primary care provider to see a specialist: Kaiser Permanente's 29 plans (you may self-refer to certain specialists) and Denver Health (Elevate)'s 8 plans (self-referral allowed for OB-GYN and outpatient mental health care). The other 111 don't, according to each plan's 2027 summary of benefits. Confirm in the plan's summary of benefits.
What a visit costs (the plan's filed "Specialist Visit" benefit, in network, before any extra savings on silver plans):
- Bronze: $100 to $140 a visit on 10 of 56 plans; on the other 46, you pay toward your deductible or a share of the bill.
- Silver: $50 to $90 a visit on 44 of 58 plans; on the other 14, you pay toward your deductible or a share of the bill.
- Gold: $50 to $90 a visit on 26 of 30 plans; on the other 4, you pay toward your deductible or a share of the bill.
In-network care costs less. Out-of-network visits on an HMO or EPO usually aren't covered except in an emergency.
In Colorado
Public records list 178 infectious disease doctors at 73 Colorado locations.
- Denver County: 19 locations
- Adams County: 9 locations
- Boulder County: 6 locations
- Jefferson County: 5 locations
- Larimer County: 5 locations
- Arapahoe County: 4 locations
Counties with the fewest: Weld (1), Teller (1), Routt (1), Rio Grande (1), Montezuma (1). 45 counties have none.
Questions to ask the office
- Do I need a referral from my primary care doctor?
- Which 2027 plans and network names do you take?
- How long is the wait for a new patient?
- Are infusion treatments given here or at a hospital?