All the business loops within New Mexico are maintained by the
New Mexico Department of Transportation (NMDOT). In New Mexico, Interstate business routes are named independently of their parent Interstate's designation with business loops of
I-25 numbered between 10 and 19, those of
I-10 between 20 and 29, and those of
I-40 between 30 and 39. New Mexico business loop numbers ascend eastward and northward with gaps in numbering to allow for future designations. I-25 begins with a business route through
Williamsburg and
Truth or Consequences before proceeding northward with additional routes serving the towns of
Socorro,
Belen,
Las Vegas,
Springer, and
Raton. These routes largely conform to the current or former alignment of the unsigned
US Highway 85 (US 85) through these communities before the construction of I-25. NMDOT has decommissioned US 85 throughout the state and no longer signs the highway along its length, as US 85 entirely follows I-25 with the single exception of the business loop in Las Vegas. The
American Association of State Highway and Transportation Officials (AASHTO), however, continues to recognize the New Mexico portion of US 85 maintaining continuity with sections in adjacent states.
Williamsburg–Truth or Consequences business loop Interstate 25 Business (
I-25 Bus.), inventoried as
Business Loop 11 (
BL 11), is a business loop serving the cities of Williamsburg and Truth or Consequences in
Sierra County. The loop begins at exit 75 of I-25 in Williamsburg, intersecting
State Road 187 (NM 187), traveling northeast on Broadway Street through Truth or Consequences until meeting Main Avenue. Between that point and Date Street, the route follows two
one-way roads with Broadway carrying northbound traffic and Main conveying traffic to the south. The routes combine and turn north on Date Street, intersecting the western terminus of
NM 51. Turning northwest, the highway intersects
NM 181 and terminates at exit 79 on I-25 on the north side of Truth or Consequences. Most of the loop, with the exception of its I-25 interchanges, was previously part of US 85, which joined the route from the south at NM 187 and departed to the north along NM 181. ;Major intersections
Socorro business loop Interstate 25 Business (
I-25 Bus.), inventoried as
Business Loop 12 (
BL 12), is a business loop serving the city of
Socorro in
Socorro County. The loop begins at exit 147 of I-25 and travels northwest along California Avenue until an
intersection with the northern terminus of
NM 1. The loop turns north as a
divided highway as it enters the city.
US 60 intersects from the west, and the loop becomes
concurrent with US 60 as the pair of highways continue to the north. The loop terminates at exit 150 on I-25, and US 60 continues along the Interstate as it exits Socorro. ;Major intersections
Belen business loop Interstate 25 Business (
I-25 Bus.), inventoried as
Business Loop 13 (
BL 13), is a business loop serving the city of Belen in
Valencia County. The loop begins at exit 190 on I-25 and intersects the northern terminus of
NM 116 as the highway travels north along Main Street into the city. The western terminus of
NM 309 is met in central Belen. The loop continues north to
NM 314 then turns northwest before terminating at exit 195 on I-25. ;Major intersections
Santa Fe business loop Interstate 25 Business (
I-25 Bus.), inventoried as
Business Loop 14 (
BL 14), was a business loop that served
Santa Fe in
Santa Fe County. The loop began at exit 278 on I-25 and traveled northeast along
NM 14 (Cerrillos Road). It then went east on
NM 466 (Saint Michaels Drive), cutting through the south side of Santa Fe. The road ended up as Old Pecos Trail and remained so until reaching I-25 again and terminating at exit 284. The route was decommissioned. ;Major intersections
Las Vegas business loop Interstate 25 Business (
I-25 Bus.), inventoried as
Business Loop 15 (
BL 15), is a business loop serving Las Vegas in
San Miguel County. It also carries unsigned
US 85. The loop begins at exit 343 of and travels northeast, intersecting
NM 329. The loop continues north, passing to the west of
Las Vegas station served by the
Southwest Chief line of
Amtrak, just south of the intersection with
NM 104. Continuing north, the highway passes east of Municipal Park before terminating at
NM 250 and I-25 at exit 347. ;Major intersections
Springer business loop Interstate 25 Business (
I-25 Bus.), inventoried as
Business Loop 16 (
BL 16), is an unsigned business loop serving the city of Springer in
Colfax County. The loop begins at exit 412 of I-25 and travels northeast along Railroad Avenue. The loop serves as the main north–south road in the town and intersects Fourth Street, which, to the west of the loop, is
NM 21 and, to the east, is
US 56 and
US 412. Continuing northwest, the loop intersects
NM 468 and then runs closely parallel to the Interstate before merging at exit 414. ;Major intersections
Raton business loop Interstate 25 Business (
I-25 Bus.), inventoried as
Business Loop 17 (
BL 17), is a business loop that begins at exit 450 on I-25 south of Raton in Colfax County concurrent with
US 64. The two highways intersect
NM 555 then pass east of La Mesa Park, traveling along Second Street north into the city. Clayton Road takes US 64 off of the loop to the east as the loop continues north, crossing over the rail line that serves
Raton station before turning northwest and terminating at exit 454 on I-25. ;Major intersections ==Colorado==