PER CURIAM.

In this workers' compensation case, the court of appeals concluded that the carrier waived its right to dispute the extent of the claimant's compensable injury by failing to adhere to Texas Labor Code section 409.021(c)'s sixty-day deadline. 325 S.W.3d 209. We recently held that the sixty-day period for challenging compensability does not apply to a dispute over extent of injury. State Office of Risk Mgmt. v. Lawton, 295 S.W.3d 646, 649-50 (Tex.2009). In light of Lawton, we reverse the court of appeals' judgment and remand this case to the trial court for further proceedings.

On January 23, 2006, Carmen Ayala injured her lower back when a window fell on her at work. Ayala was originally diagnosed with a back sprain/strain. On March 1, Zenith received notice of Ayala's injury and commenced paying benefits. On April 13, Ayala's original diagnosis was revised to include lumbar radicular syndrome. A week later, her diagnosis was again amended to also include lumbar spondylolisthesis.1 To treat Ayala, physicians recommended an epidural steroid injection, a procedure requiring Zenith's preauthorization. On April 27, Zenith preauthorized the treatment, and the injection was performed. On July 28, Zenith notified Ayala that it was disputing her entitlement to benefits for the lumbar condition because the condition was degenerative and not the result of the January 23 injury.

The Texas Department of Insurance, Division of Workers' Compensation (the Division), held a contested case hearing to determine whether Ayala's compensable injury included the lumbar condition and whether Zenith had waived its right to contest compensability by not complying with Labor Code section 409.021(c)'s deadline. The parties stipulated that: (1) Ayala sustained a compensable injury; (2) Zenith received notice of Ayala's injury on March 1; (3) Zenith was not contesting compensability; and (4) Zenith did not dispute that the compensable injury included the lumbar condition until July 28. The hearing officer concluded that, although Ayala failed to prove the compensable injury event was a producing cause of the lumbar condition, it was nevertheless compensable because Zenith failed to dispute compensability within sixty days after it received notice of Ayala's initial injury. The Division appeals panel affirmed, and Zenith sought judicial review.

On competing motions for summary judgment, the trial court held Zenith waived its right to contest compensability by not timely disputing the lumbar condition diagnosis in accordance with Labor Code section 409.021. Thus, the compensable injury extended to include the lumbar condition. The court of appeals affirmed. 325 S.W.3d 209. We reverse.

In Lawton, we answered the same issue presented today: "whether the sixty-day period for challenging compensability of an injury also applies to a dispute over the extent of injury, if the basis for that dispute could have been discovered by a reasonable investigation within the waiver period." Lawton, 295 S.W.3d at 647. We held that section 409.021(c)'s sixty-day deadline2 applies only to compensability disputes, not disputes over the extent of an injury.3 Id. at 649-50. Instead, when a carrier disputes extent of injury, it "has up to forty-five days from the date it receives a complete medical bill to dispute whether that treatment was necessary." Id. at 650.

Ayala argues that Lawton is inapplicable because this is not an extent of injury dispute, but rather a compensability case. We disagree. As the Division explains:

25 Tex. Reg. 2096, 2097 (2000)(quoted in Lawton, 295 S.W.3d at 649). Here, Zenith agreed that Ayala's initial injury, a back sprain/strain, was compensable; Zenith disputed only the subsequently added diagnoses. This mirrors the Division's conception of an extent of injury dispute as well as the facts of Lawton4:

25 Tex. Reg. at 2097. Thus, unlike compensability, extent of injury disputes arise when the carrier believes additional conditions are unrelated to the compensable injury. Because this is an extent of injury dispute, section 409.021(c)'s sixty-day deadline does not apply, and Zenith "has up to forty-five days from the date it receives a complete medical bill to dispute whether [the] treatment [for the lumbar condition] was necessary." Lawton, 295 S.W.3d at 650.

Ayala also asserts that this case is distinguishable from Lawton because, here, Zenith preauthorized the epidural steroid injection to treat Ayala. We disagree. Under Division rules, a "carrier shall approve or deny requests [for preauthorization] based solely upon the medical necessity of the health care required to treat the injury, regardless of: (1) unresolved issues of compensability, extent of or relatedness to the compensable injury; (2) the carrier's liability for the injury; or (3) the fact that the employee has reached maximum medical improvement." 28 TEX. ADMIN.CODE § 134.600(h). Preauthorization does not, in and of itself, make the carrier liable. See id. § 134.600(d) ("The carrier is not liable ... if there has been a final adjudication that the injury is not compensable or that the health care was provided for a condition unrelated to the compensable injury."). Instead, preauthorization merely precludes a carrier from later disputing the medical necessity of the treatment. See TEX. LAB.CODE § 413.014(e). A carrier, upon receipt of the bill for preauthorized treatment, may still argue that the condition treated is not related to the compensable injury. See 28 TEX. ADMIN.CODE § 134.600(d). As the Division explains:

25 Tex. Reg. at 2101. Thus, Zenith's preauthorization does not preclude Zenith from disputing extent of injury in this case.

Because this dispute involves extent of injury, rather than compensability, section 409.021(c)'s sixty-day deadline is inapplicable. Without hearing oral argument, we reverse the court of appeals' judgment and remand the case to the trial court for further proceedings. TEX.R.APP. P. 59.1, 60.2(d).