Yes — but not in the way most employers expect. Federal rules set a small group’s rating area from the employer’s principal business address, and CMS draws the Texas rating areas on county lines. So the county attached to your business address can change the area you are rated in, while the city name on your letterhead settles nothing.
The address the rating area comes from, and whose address it is
A small group’s rating area is not chosen by the employer and it is not chosen by the carrier. It is determined by rule, and the rule names one address:
“In the small group market, using the group policyholder’s principal business address. For purposes of this paragraph (a)(1)(ii)(B), principal business address means the principal business address registered with the State or, if a principal business address is not registered with the State, or is registered solely for purposes of service of process and is not a substantial worksite for the policyholder’s business, the business address within the State where the greatest number of employees of such policyholder works. If, for a network plan, the group policyholder’s principal business address is not within the service area of such plan, and the policyholder has employees who live, reside, or work within the service area, the principal business address for purposes of the network plan is the business address within the plan’s service area where the greatest number of employees work as of the beginning of the plan year. If there is no such business address, the rating area for purposes of the network plan is the rating area that reflects where the greatest number of employees within the plan’s service area live or reside as of the beginning of the plan year.”
— 45 C.F.R. § 147.102(a)(1)(ii)(B)
Read in order, that subparagraph sets a priority. It names the registered principal business address first. It falls back to the worksite where the greatest number of employees work only when the registered address is absent, or is a registration for service of process rather than a real place of business. And it reaches employee residence only inside the narrow network-plan path at the end, where the employer’s principal business address sits outside the plan’s service area.
For most Texas employers buying a group health plan, the practical upshot is short: the address on the registration is the address that decides, and the county that address sits in is the unit the rating table actually knows.
Counties, not cities — what the CMS table for Texas contains
CMS publishes the Texas Geographic Rating Areas, and the page introduces the table in its own words as the state specific geographic rating areas, including specific geographic divisions for the Individual and Small Group market in Texas. The table has two columns — a rating area identifier and a county name — and nothing else.
That table carries 27 rating areas across 254 county rows (Texas Geographic Rating Areas), one row per county, and every Texas county appears exactly once and is assigned to exactly one area. CMS’s parent table of state rating areas, Market Rating Reforms, carries a Texas row with the same area count and the market geographic rating division recorded as Counties.
There is no three-digit zip code column on the Texas table. A case-insensitive sweep of the whole page for the word zip returns nothing, against a positive control of every county name on the page. That matters because a zip code is the first thing an employer reaches for, and in Texas it is not what the table is keyed on.
Houston: one city, and the city name does not settle the area
Houston’s city limits lie in Harris, Fort Bend and Montgomery counties. The Texas record ties the city to each of those counties through the Comptroller’s own city sales and use tax schedule, which lists the city separately under each. CMS puts Harris, Fort Bend and Montgomery in different rating areas.
So two Houston employers with Houston mailing addresses, both inside the city, can be rated in different areas. Harris itself shares its rating area with Galveston and nothing else. The words “Houston, TX” do not settle the rating area. The county does.
Dallas and Fort Worth: the line runs through the city, not between the cities
Dallas’s city limits lie in Dallas, Collin, Denton, Kaufman and Rockwall counties. CMS places the Dallas, Collin, Kaufman and Rockwall portions in one rating area and the Denton County portion in another — and the other one is the area that carries Fort Worth.
Fort Worth’s own limits reach Tarrant, Denton, Parker and Wise counties, and CMS puts all of those in one area. Read the two together and the Metroplex behaves backward from the way people describe it: the rating line does not sit between Dallas and Fort Worth. It runs through the City of Dallas, because Dallas’s Denton County part is rated with Fort Worth. Two employees of one Dallas employer can sit in different rating areas without either of them leaving the city.
Austin, Amarillo and the cities where crossing a county line changes nothing
The opposite case is just as common and is the more useful half of the answer.
Austin’s limits lie in Travis and Williamson counties, with part of the city in Hays. CMS places Travis, Williamson and Hays in the same rating area, so the whole corridor from Round Rock and Georgetown down to Kyle and San Marcos holds one area factor.
Amarillo straddles the Potter–Randall county line, and CMS places Potter and Randall in the same area, which takes in the surrounding Panhandle counties. Unlike Dallas, the straddle changes nothing.
Fort Worth, as above, spreads across county lines without crossing a rating line at all.
So there is no general Texas rule in either direction. Crossing a county line sometimes moves the rating area and sometimes does not, and the only way to know is to look up the county.
El Paso, San Antonio and the Rio Grande Valley
El Paso lies in El Paso County alone, and its rating area contains no other Texas metro — the counties sharing it are Hudspeth, Culberson, Jeff Davis, Presidio and Brewster. An employer weighing an El Paso site against a Dallas or Houston site is looking at rating areas that share no counties.
San Antonio lies in Bexar County alone, in an area running from the Hill Country to the Rio Grande that includes Val Verde, Kinney, Maverick, Dimmit and Zavala. An employer there can place staff across New Braunfels, Seguin, Boerne and Kerrville without the area moving.
The Valley is the sharpest case. McAllen sits in Hidalgo County, which CMS groups with Starr and Brooks. Cameron County — Brownsville and Harlingen — is a different area, grouped with Willacy and Kenedy. Two sites in the same labor market on the same river are quoted on two area factors.
What no source will tell you, and we will not either
Area assignment exists and it is determined by a published rule. What the public record does not contain is any ranking of Texas rating areas by price. No source in our Texas research publishes a premium level by rating area, and we looked. That means nobody can responsibly tell you that a named Texas county, city or area is cheaper or more expensive than another, and this page does not.
What you can do with the county is narrower and more honest: know which area your address puts you in, know whether a second location or a registered-agent address would put you somewhere else, and make sure every proposal you receive was built on the same one. That is a real thing to check when you are shopping a renewal and it costs nothing to confirm.
The date on the CMS page, and what it does not say
The Texas rating-area page carries exactly one date on its face, and it is a page modification stamp reading September 10, 2024. It states no effective plan year, carries no applicability language and has no revision history. CMS’s parent table carries its own caption, updated in September 2022, and its Texas row still agrees with the Texas page parsed today.
So we will not describe these as the current-year rating areas, and you should be careful of any source that does. What is affirmable is what the pages say: the areas are drawn on counties, every Texas county is assigned, and the two CMS documents agree with each other.
Before you ask anyone for a quote
Work through these in order.
Find the county of the address that is actually registered for your business, and confirm it is a substantial worksite rather than a service-of-process registration. Look that county up on the CMS Texas table and note the area it belongs to. Then, if you run more than one location in Texas, do the same for the second address, because the rule keys on the principal business address rather than on the largest one, and in Houston or Dallas the two can be in different areas inside one city.
Our Texas page carries the state-level detail, and if you would rather have someone else read the table for you, that is what a quote request is for.
The bottom line
In Texas the rating area follows the county of your principal business address, and a city name does not settle it. Houston and Dallas straddle rating lines; Fort Worth, Austin and Amarillo do not. Confirm the county before you compare quotes.
Frequently asked questions
Does my county really change my group health rate in Texas?
Your county decides which geographic rating area your small group is placed in, because CMS draws the Texas rating areas on county lines and federal rules set the small group rating area from the group policyholder’s principal business address. Which area you land in is a structural input to the rate. No published source ranks Texas rating areas against one another, so nobody can honestly tell you a named county is cheaper than another.
Is it my county or my employees’ counties that matter?
For the small group market the federal rule names the group policyholder’s principal business address — the employer’s address, not each employee’s. Employee residence enters only through a narrow network-plan fallback the rule spells out, which applies where the principal business address sits outside the plan’s service area.
Houston, Dallas, Austin — does the city name settle the rating area?
No. The CMS table for Texas knows counties, not cities. Houston’s limits reach Harris, Fort Bend and Montgomery counties, which CMS places in different rating areas, and the Dallas–Fort Worth rating line runs through the City of Dallas because the Denton County part of Dallas is rated with Fort Worth. Austin, Fort Worth and Amarillo cross county lines without crossing a rating line.
Where do I look up my own county’s rating area?
CMS publishes the Texas table itself at https://www.cms.gov/cciio/programs-and-initiatives/health-insurance-market-reforms/tx-gra. Every Texas county appears there exactly once beside the rating area it belongs to. Find the county of your registered principal business address, not the county of your largest job site or of your own home.
Which Texas county is the cheapest for small group health insurance?
That question has no sourced answer and we will not invent one. No source we can cite publishes premium levels by Texas rating area, so no county, city or area can be described here as cheaper or more expensive than another. What the public record supports is that area assignment exists and how it is determined.
About the author
Nate Jones, CPCU, is the founder of Wexford Insurance and Wexford Health Insurance, an independent agency placing small-business group benefits in 9 states. Nate reads the CMS geographic rating area table for Texas county by county before quoting a group, because a Houston or Dallas address can sit on either side of a rating line without leaving the city. Start with the Wexford Health Insurance quote form.