The claimant in this workers’ compensation action was injured ii early 1991. In an earlier proceeding, the board ruled that becaus claimant’s employer failed to explain the panel of physicians to hir and subsequently controverted his claim, claimant was entitled t choose his own treating physician. This ruling was affirmed by th superior court and we denied employer’s application for discretionar review in August 1992. Thus, the issue of employer’s liability for th disputed claim was resolved and employer was paying for claimant’ medical care in February 1993, when claimant changed treating phy sicians. Because claimant failed to seek board authorization for thi change pursuant to OCGA § 34-9-200 (b), employer refused to pa for the new physician’s treatment. Claimant took his claim to th board and convinced it that such authorization was not necessary The superior court reversed, however, holding that board authoriz; tion was necessary for a change of physicians under these circuir stances. We granted this discretionary appeal to determine whethe the superior court’s holding was correct, and we now affirm.

1. Claimant argues that because he had the right to choose h: original treating physician, he has absolute control over his medic; treatment and can change his treating physician whenever he wan1 until he has completely recovered from his injury. 1 The latter dot *823 not necessarily follow from the former, however. See Chesapeake Masonry Corp. v. Wiggington, 327 SE2d 121 (Va. 1985) (even though claimant had right to choose treating physician because employer denied his claim and failed to provide panel, once claimant chose doctor that doctor became his authorized treating physician, and claimant could not refuse his care and change to another doctor without approval); cf. also Worley Bros. Granite Co. v. Hall, 109 Ga. App. 720 (137 SE2d 312) (1964) (even though employer allowed claimant to choose his original treating physician, claimant did not have right to change to another physician without approval).

As a general rule, a claimant cannot change to a new treating physician without petitioning the board for approval under OCGA § 34-9-200 (b). See Holcombe v. Brown Transp. Corp., 253 Ga. 719 (324 SE2d 446) (1985); OCGA § 34-9-201 (e) (previously OCGA § 34-9-201 (d)). Nonetheless, if the employer is failing to provide medical care, the claimant need not seek approval before going to a new doctor, and the employer cannot later complain that the treatment was unauthorized. See Boaz v. K-Mart Corp., 254 Ga. 707 (1) (334 SE2d 167) (1985); Ga. Power Co. v. Brasill, 171 Ga. App. 569 (320 SE2d 573) (1984), aff’d, 253 Ga. 766 (327 SE2d 226) (1985); Capital Atlanta v. Carroll, 213 Ga. App. 214 (2a) (444 SE2d 592) (1994). This is because the statutory requirement of petitioning for approval of a change “presupposes present treatment is being allowed and is appropriate only if existing medical assistance still continues.” Brasill, 171 Ga. App. at 570.

The timing of the employer’s failure to provide care is crucial, íowever; where the claimant changes doctors at a time the employer s providing medical care, the employer’s subsequent termination of nedical care and controversion of the claim does not excuse the claimant’s failure to petition for a change “at the time other medical services were sought.” K-Mart Corp. v. Anderson, 166 Ga. App. 421, 123 (304 SE2d 526) (1983). Cf. State of Ga. v. Tungler, 181 Ga. App. 11 (1) (351 SE2d 248) (1986); Scandrett v. Talmadge Farms, 174 Ga. App. 547 (2) (330 SE2d 772) (1985) (both holding that claimant can-lot ignore panel and choose own doctor before employer has opportu-lity to furnish treatment and refuses to do so).

*824 Thus, the pivotal question is whether the employer was providin medical care at the time the claimant changed doctors: if so, th claimant was required to petition the board for approval before h could change physicians or treatment. Cf. Boaz, 254 Ga. at 709-71 (emphasizing that the claimant could choose a new doctor because h was not currently receiving treatment from authorized treating phys: cian); Capital Atlanta, 213 Ga. App. at 216 (3a) (holding petition fc approval of referral was not necessary because employer had contrc verted claim “at the time of the referral”).

In this case, employer was providing medical care for claimant £ the time claimant changed physicians. Just as a subsequent refusal t provide medical care does not excuse a claimant from petitioning fc a change if the employer was providing care at the time of the chang neither does a prior refusal to provide benefits excuse the claimax from filing such a petition once the dispute is resolved in the clain ant’s favor and the employer is providing medical care. According! the superior court was correct in its ruling that the new physician treatment was unauthorized.

2. Claimant also contends he had the right to change physiciar once without board authorization under Board Rule 201 (e). Th rule, which became effective in July 1992, provides that “[w]hen case has not been controverted . . . and when the employer did n< have a posted panel or had an invalid panel, the employee is autho ized to select a physician who is not listed on the employer’s pane That physician so selected becomes the authorized treating physicia and the employee may make one change from that physician to ai other physician without approval of the employer and without an o der from the board.” It is arguable that this rule is invalid because enlarges the substantive rights of claimants, see Holt Svc. Co. v. Motlin, 163 Ga. App. 283 (1) (293 SE2d 741) (1982); and it is furth arguable that the rule would not apply here anyway, since claimant right to choose his original treating physician was based not on er ployer’s failure to post a valid panel but on its failure to adequate explain the panel, as well as its subsequent controversion of tl claim. 2 Even assuming that the rule is valid and otherwise applicab] however, we conclude that the rule would not apply here becau claimant’s injury occurred before the rule became effective, and t rule cannot be retroactively applied. See Hall v. Hartford Ins. Grou 146 Ga. App. 751 (247 SE2d 570) (1978).

Judgment affirmed.