NPI age
13 years
Enumerated 2013-04-25
● Active
Type 1 · Individual
Mark Jeffery Irby, PA-C
Irby is 1 of 494 physician assistant providers in Houston and 1 of 1890 in Texas.
Primary specialty
Physician Assistant
Plus 1 subspecialty
Licensed in
TX, OR
2 states
Status
Active
No deactivations on record
Last NPPES update
2026-03-11
Source: monthly bulk 2026-05
Sole proprietor
No
May be part of a larger org
How this provider compares
Across 1890 active physician assistant providers in Texas.
NPI age
13 years
↑ 2 yr above median (11 yr)
State licenses
2 states
Top 94% — 5% of peers are multi-state
Subspecialties
1
In the 32% of peers with subspecialties
NPI lifetime · 2013 → 2026
2013-04Enumerated in NPPES
2013
2026
Where they practice
Practice location
6400 Fannin St, Ste 1700
Houston, TX 770301521
Mailing address
7401 Sw Washo Ct Ste 100
Tualatin, OR 970628342
Additional practice locations
3 secondary locations on file with NPPES.
Location 2
1508 Division St Ste 105
Oregon City, OR 970451584
Location 3
6485 Sw Borland Rd Ste A
Tualatin, OR 970629762
Location 4
7401 Sw Washo Ct Ste 100
Tualatin, OR 970628342
Specialties
-
Physician Assistant PrimaryDefinition to come...
-
Physician AssistantA physician assistant is a person who has successfully completed an accredited education program for physician assistant, is licensed by the state and is practicing within the scope of that license. Physician assistants are formally...
Practice context
Part of a multi-provider practice. 171 other active providers share this practice address in NPPES.
Recently enumerated nearby: 7 new physician assistant providers have been added in Houston in the last 180 days.
See all →
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- Confirm the NPI on NPPES.The CMS registry is the system of record. Open NPPES →
- Check the state license is currently active.State licensing boards publish current status; NPPES does not.
- Confirm payer enrollment if billing.NPI presence does not guarantee active enrollment with Medicare, Medicaid, or commercial payers.